Red mud modified ceramic matrix composite material and application thereof in concrete

Abstract

The invention discloses a red mud modified ceramic-based composite material and application thereof in concrete, and belongs to the technical field of preparation of materials for concrete. Levodopa, a silane coupling agent, EDC hydrochloride and N-hydroxysuccinimide are subjected to a reaction, and a modified silane coupling agent is obtained; reacting the modified silane coupling agent with the red mud particles to obtain modified red mud; reacting the modified silane coupling agent with ceramic waste to obtain modified ceramic waste; the modified red mud, the modified ceramic waste and water react to obtain mixed slurry, and the mixed slurry is subjected to centrifugal separation, drying and dehydration and then subjected to high-temperature sintering to obtain the ceramic-based composite material. The concrete prepared by the invention not only has good porosity, but also has good mechanical performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of material preparation for concrete, and particularly relates to a red mud modified ceramic matrix composite material and application thereof in concrete. BACKGROUND

[0002] With the acceleration of urbanization, the demand for building materials is increasing, and traditional concrete gradually exposes problems due to its high self-weight and poor water permeability. In order to cope with this challenge, porous concrete as a new type of building material gradually attracts attention. Porous concrete not only has good structural strength, but also has superior water permeability and lightweight characteristics, becoming an indispensable material in modern construction and infrastructure. The main raw materials of porous concrete include cement, aggregate, additives and water, etc., and its porosity is usually between 15% and 30%. Due to its high porosity, porous concrete has the following several significant effects: (1) water permeability: one of the important characteristics of porous concrete is its good water permeability, which can effectively control rainwater runoff, reduce urban flood disasters, and improve urban water circulation; (2) lightweight: compared with traditional concrete, porous concrete has lower density due to the existence of internal pores, which makes it possible to reduce the self-weight and reduce the foundation load in building applications; (3) thermal insulation: the pore structure of porous concrete can effectively reduce heat conduction and improve the thermal insulation performance of buildings, saving energy; (3) acoustic performance: porous concrete can absorb part of the sound wave and reduce noise pollution, which is suitable for noise control in urban environment.

[0003] Although the porous structure has the above excellent performance, at the same time, due to the existence of more pore structure, sometimes it also affects the strength performance of the concrete, and further makes the mechanical performance of the concrete poor. Patent CN116477967A discloses a porous fly ash modified foam concrete, its preparation method and application. The invention mixes foaming agent, nano foam stabilizer, a small amount of porous fly ash and a small amount of silica fume, adds appropriate tap water to prepare foaming liquid; mixes the remaining tap water with cement, fly ash, remaining porous fly ash, remaining silica fume and formic acid, and stirs uniformly to form a slurry; places the foaming liquid in a foaming machine to generate foam, and adds it to the slurry and stirs uniformly to obtain porous fly ash foam concrete. The combination of porous fly ash and silica fume improves the stability of foam, and porous fly ash not only participates in hydration, but also adjusts the water balance in the system to promote the hydration of foam concrete. Porous fly ash combined with formic acid can adjust the setting time of the matrix and the yield stress of the matrix, and can significantly improve the stability, pore structure and physical and mechanical properties of foam concrete; and porous fly ash not only reduces the self-weight of foam concrete, but also improves the strength and stability of foam concrete.

[0004] Red mud is an industrial solid waste discharged after extracting alumina from bauxite, mainly including SiO2, Al2O3, CaO, Fe2O3, etc., and has a certain strength. However, due to the difficulty in treatment, the accumulation and storage will cause serious pollution to the environment, and also cause resource waste. Ceramic waste mainly refers to a kind of industrial products and waste residues discarded in the production process of ceramic products due to unqualified products in the processes of forming, drying, glazing, handling, firing and storage, and has a certain strength and firmness. The ceramic waste is often discarded as an industrial by-product, causing resource waste. How to utilize the red mud and ceramic waste to improve the mechanical properties of porous concrete has practical research and application value. SUMMARY

[0005] According to the deficiencies of the prior art, the red mud and the ceramic waste are modified respectively to obtain modified red mud and modified ceramic waste, the modified red mud and the modified ceramic waste are mixed to prepare a ceramic-based composite material, and then the ceramic-based composite material is mixed with cement, river sand, water and an air entraining agent composition to complete the preparation of the concrete, thereby solving the technical problems in the background art. Specifically, the technical scheme of the present application includes the following contents: A red mud modified ceramic-based composite material, and a preparation method thereof, includes the following steps: The levodopa, the silane coupling agent, the EDC hydrochloride and the N-hydroxysuccinimide are mixed and reacted in a mass ratio of 1:0.8-1:2-3:2.5-3.5 to obtain a modified silane coupling agent; The modified silane coupling agent and the red mud particles are mixed and reacted in a weight ratio of 1:70-80 to obtain modified red mud; The modified silane coupling agent and the ceramic waste are mixed and reacted in a weight ratio of 1:50-60 to obtain modified ceramic waste; The modified red mud, the modified ceramic waste and water are mixed and reacted in a weight ratio of 1:6-8:20-30 to obtain a mixed slurry, and the mixed slurry is centrifuged and dried after dehydration, and then high-temperature sintering is performed to obtain a ceramic-based composite material.

[0006] Further, the silane coupling agent includes γ-aminopropyltrimethoxysilane or γ-aminopropyltriethoxysilane, which needs to have an amino group for introducing levodopa onto the silane coupling agent through an amidation reaction.

[0007] Further, the mixing and reaction conditions of the levodopa, the silane coupling agent, the EDC hydrochloride and the N-hydroxysuccinimide include a reaction temperature of 30-35°C and a reaction time of 5-7h.

[0008] Further, the preparation of the red mud particles includes the following steps: After the red mud is dried to constant weight, it is crushed and then put into a grinder to obtain a powder, and the powder is sieved through a 100-mesh screen to obtain red mud particles.

[0009] Further, the conditions for mixing and reacting the modified silane coupling agent and the red mud particles include a reaction temperature of 110-120 DEG C and a reaction time of 40-60 min.

[0010] Further, the method for preparing the ceramic waste material includes the following steps: The green body waste material is crushed and sieved through a square hole screen with a diameter of 9.5 mm to obtain the ceramic waste material.

[0011] Further, the green body waste material is a waste material formed before a ceramic product is fired, and is one of ceramic waste materials, and has no particularity.

[0012] Further, the conditions for mixing and reacting the modified silane coupling agent and the ceramic waste material include a reaction temperature of 80-90 DEG C and a reaction time of 3-4 h.

[0013] Further, the conditions for mixing and reacting the modified red mud, the modified ceramic waste material and water include a reaction pH value of 8.5-9, a reaction temperature of 25-30 DEG C and a reaction time of 10-12 h.

[0014] Further, the conditions for high-temperature sintering include a sintering temperature of 900-1000 DEG C and a sintering time of 60-70 min.

[0015] An application of a red mud modified ceramic matrix composite in concrete, the application including the following steps: The cement, river sand, ceramic matrix composite, water and air entraining agent composition are mixed and stirred according to a weight ratio of 20-22:35-37:3-5:9-10:0.6-0.8 to obtain the concrete.

[0016] Further, the cement is a portland cement with a strength grade of 42.5.

[0017] Further, the air entraining agent composition is composed of sodium dodecyl sulfonate, sodium lignosulfonate and polyether defoaming agent XPJ890 according to a weight ratio of 1:1:0.5.

[0018] Compared with the prior art, the application has the following beneficial effects: The present application firstly modifies the silane coupling agent containing amino and levodopa by mixing reaction, so that the structure of the silane coupling agent is modified by levodopa to obtain a modified silane coupling agent. Then, the modified red mud and the modified ceramic waste are mixed and bonded by the oxidation and self-polymerization of levodopa in an alkaline environment to form a mixed slurry, which improves the interfacial bonding between the two. Although dopamine also has an adhesive polydopamine structure formed by oxidation and self-polymerization, it is difficult to modify the silane coupling agent due to the lack of carboxyl groups in the structure. After the mixed slurry is dehydrated and sintered at high temperature, a ceramic matrix composite is formed. Finally, the ceramic matrix composite is mixed with cement, river sand, water and air entraining agent composition, so that the mechanical properties of the prepared concrete are greatly improved. DETAILED DESCRIPTION

[0019] The technical solutions of the present application will be described clearly and completely through the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] Unless otherwise specified, the raw materials and reagents used in the present application are commercially available or can be prepared by known methods.

[0021] Preparation Example 1: The preparation method of the red mud particles specifically includes the following steps: The red mud was dried to constant weight in a temperature environment of 110°C to remove surface moisture, then the dried red mud was crushed with a crusher at a speed of 750 r / min, and then put into a grinding machine to grind at a speed of 1500 r / min for 30 min. After grinding, the powder was collected, and the powder was sieved with a 200 mesh screen to obtain red mud particles.

[0022] Preparation Example 2: The preparation method of the red mud particles specifically includes the following steps: The red mud was dried to constant weight in a temperature environment of 110°C to remove surface moisture, then the dried red mud was crushed with a crusher at a speed of 750 r / min, and then put into a grinding machine to grind at a speed of 1500 r / min for 30 min. After grinding, the powder was collected, and the powder was sieved with a 200 mesh screen to obtain red mud particles.

[0023] Preparation Example 3: The preparation method of ceramic waste material specifically comprises the following steps: First, the body waste material is broken with a hammer, and then is crushed in a crusher with a rotation speed of 1000 r / min. The crushed body waste material is screened with a square hole sieve with a diameter of 9.5 mm to obtain the ceramic waste material.

[0024] Example 1 A red mud modified ceramic matrix composite material specifically comprises the following process: 0.2 mol of levodopa is weighed and added to a flask containing 400 mL of anhydrous acetone. Then, 0.4 mol of EDC hydrochloride and 0.5 mol of N-hydroxysuccinimide are weighed and added to the flask to disperse with levodopa under the ultrasonic power of 300 W for 20 min to obtain a dispersion liquid. Then, the pH of the dispersion liquid is adjusted to 4.5 with dilute hydrochloric acid, and the dispersion liquid is placed in a water bath at 25℃ for pre-activation treatment for 1 h. After the pre-activation treatment, 0.16 mol of γ-aminopropyltrimethoxysilane is added, mixed and dispersed uniformly, and the pH is adjusted to neutral. Then, the mixture is placed in a water bath at 30℃, and the timed reaction is performed for 5 h. After the reaction is completed, water is added to mix and stir until the layers are separated. The organic layer is collected, and the organic layer is evaporated under reduced pressure to obtain a modified silane coupling agent. 1 part by weight of the modified silane coupling agent and 70 parts by weight of the red mud particles obtained in Preparation Example 1 are weighed and added to a mortar for grinding for 20 min to make them fully mixed. After mixing, the mixture is sent to an electric heating drying box, and the temperature is raised to 110℃ at a heating rate of 5℃ / min, and the timed reaction is performed for 40 min. After the reaction is completed, the mixture is naturally cooled to room temperature to obtain the modified red mud for use. 1 part by weight of the modified silane coupling agent and 50 parts by weight of the ceramic waste material obtained in Preparation Example 3 are weighed and added to a mortar for grinding for 40 min to make them fully mixed. After mixing, the mixture is sent to an electric heating drying box, and the temperature is raised to 80℃ at a heating rate of 5℃ / min, and the timed reaction is performed for 3 h. After the reaction is completed, the mixture is naturally cooled to room temperature to obtain the modified ceramic waste material for use. 1 part by weight of the modified red mud, 6 parts by weight of the modified ceramic waste material are weighed and added to 20 parts by weight of deionized water, and then dispersed by ultrasonic power of 600 W for 30 min. After the dispersion treatment is completed, ammonia water is added to adjust the pH to 8.5, and then the mixture is mixed and stirred at a temperature of 25℃ for 10 h. After the reaction is completed, the mixed slurry is first separated by a centrifuge to obtain a solid precipitate. The solid precipitate is placed in an oven at 110℃ for drying and dehydrating for 2 h, and then is taken out and sintered at a high temperature of 900℃ for 60 min. After the sintering is completed, the mixture is naturally cooled to room temperature to obtain a ceramic matrix composite material.

[0025] Example 2 A red mud modified ceramic matrix composite material specifically comprises the following process: Take 0.2 mol of levodopa and add it to a flask containing 400 mL of anhydrous acetone. Then take 0.5 mol of EDC hydrochloride and 0.6 mol of N-hydroxysuccinimide and add them to the flask to disperse with levodopa under a 300 W ultrasonic power for 20 min to obtain a dispersion. Then adjust the pH of the dispersion to 4.5 with dilute hydrochloric acid and place it in a water bath at 25°C for pre-activation for 1 h. After the pre-activation treatment is completed, add 0.18 mol of γ-aminopropyltrimethoxysilane and mix well. Adjust the pH to neutral, then place it in a water bath at 30°C for timed reaction for 6 h. After the reaction is completed, add water and mix well until the layers are separated. Collect the organic layer and evaporate it under reduced pressure to obtain a modified silane coupling agent. Take 1 part by weight of the modified silane coupling agent and 75 parts by weight of the red mud particles obtained in Preparation Example 1 and add them together to a mortar and grind for 20 min to mix them well. After mixing, put them into an electric heating drying oven and heat them to 115°C at a heating rate of 5°C / min and react for 50 min. After the reaction is completed, naturally cool them to room temperature to obtain modified red mud for use. Take 1 part by weight of the modified silane coupling agent and 55 parts by weight of the ceramic waste obtained in Preparation Example 3 and add them together to a mortar and grind for 40 min to mix them well. After mixing, put them into an electric heating drying oven and heat them to 85°C at a heating rate of 5°C / min and react for 3.5 h. After the reaction is completed, naturally cool them to room temperature to obtain modified ceramic waste for use. Take 1 part by weight of the modified red mud and 7 parts by weight of the modified ceramic waste and add them to 25 parts by weight of deionized water. Then disperse them by ultrasonic power of 600 W for 30 min. After the dispersion treatment is completed, add ammonia to adjust the pH to 8.5. Then control the temperature at 25°C and mix and stir them to react for 11 h. After the reaction is completed, separate the mixed slurry by centrifugation to obtain a solid precipitate. Put the solid precipitate into an oven at 110°C and dry it for 2 h. Then take it out and sinter it at a high temperature of 950°C for 65 min. After the sintering is completed, naturally cool it to room temperature to obtain a ceramic matrix composite material.

[0026] Example 3: A red mud modified ceramic matrix composite material, specifically comprising the following processes: Take 0.2 mol of levodopa and add it to a flask containing 500 mL of anhydrous acetone. Then take 0.6 mol of EDC hydrochloride and 0.7 mol of N-hydroxysuccinimide and add them to the flask to disperse with levodopa under a ultrasonic power of 300 W for 20 min to obtain a dispersion. Then adjust the pH of the dispersion to 4.5 with dilute hydrochloric acid and place it in a water bath at 25℃ for pre-activation for 1 h. After the pre-activation is completed, add 0.2 mol of γ-aminopropyl triethoxysilane and mix well. Adjust the pH to neutral, and then place it in a water bath at 35℃ for timed reaction for 7 h. After the reaction is completed, add water and mix well until the layers are separated. Collect the organic layer and evaporate it under reduced pressure to obtain a modified silane coupling agent. Take 1 part by weight of the modified silane coupling agent and 80 parts by weight of the red mud particles obtained in Preparation Example 1 and add them together to a mortar for grinding for 20 min to mix them well. After mixing, put them into an electric heating drying oven, heat them to 120℃ at a heating rate of 5℃ / min, and time the reaction for 60 min. After the reaction is completed, naturally cool them to room temperature to obtain modified red mud for use. Take 1 part by weight of the modified silane coupling agent and 60 parts by weight of the ceramic waste obtained in Preparation Example 3 and add them together to a mortar for grinding for 40 min to mix them well. After mixing, put them into an electric heating drying oven, heat them to 90℃ at a heating rate of 5℃ / min, and time the reaction for 4 h. After the reaction is completed, naturally cool them to room temperature to obtain modified ceramic waste for use. Take 1 part by weight of the modified red mud and 8 parts by weight of the modified ceramic waste and add them to 30 parts by weight of deionized water. Then disperse them by ultrasonic power of 600 W for 30 min. After the dispersion is completed, add ammonia water to adjust the pH to 9. Then control the temperature at 30℃ and mix them for reaction for 12 h. After the reaction is completed, separate the mixed slurry by a centrifuge to obtain a solid precipitate. Put the solid precipitate into an oven at 110℃ for drying and dehydrating for 2 h. Then take it out and sinter it at a high temperature of 1000℃ for 70 min. After the sintering is completed, naturally cool it to room temperature to obtain a ceramic matrix composite material.

[0027] Comparative Example 1 A red mud modified ceramic matrix composite material, specifically comprising the following processes: Replace the red mud particles in Example 3 with the red mud particles obtained in Preparation Example 2, and keep the rest of the preparation process consistent with Example 3.

[0028] Comparative Example 2 A red mud modified ceramic matrix composite material, specifically comprising the following processes: 0.2 mol of levodopa and 0.2 mol of γ-aminopropyltriethoxysilane were weighed and added to a flask containing 500 mL of anhydrous acetone. 0.6 mol of EDC hydrochloride and 0.7 mol of N-hydroxysuccinimide were then added to the flask and dispersed with the levodopa under 300 W ultrasonic power for 20 minutes to obtain a dispersion. The pH of the dispersion was then adjusted to 4.5 with dilute hydrochloric acid and placed in a 35°C water bath for a timed reaction of 7 hours. After the reaction was completed, water was added and the mixture was stirred until layers separated. The organic layer was collected and evaporated under reduced pressure to obtain a modified silane coupling agent. Weigh 1 part by weight of the modified silane coupling agent and 80 parts by weight of the red mud particles obtained in Preparation Example 1 in a mortar and grind for 20 minutes to thoroughly mix. After mixing, place the mixture in an electric drying oven and heat it to 120°C at a rate of 5°C / min. The reaction time was measured for 60 minutes. After the reaction was complete, the mixture was naturally cooled to room temperature to obtain the modified red mud for later use. Weigh 1 part by weight of the modified silane coupling agent and 60 parts by weight of the ceramic scrap obtained in Preparation Example 3 in a mortar and grind for 40 minutes to thoroughly mix. After mixing, place the mixture in an electric drying oven and heat it to 90°C at a rate of 5°C / min for 4 hours. After the reaction is complete, cool the mixture to room temperature to obtain the modified ceramic scrap. One part by weight of modified red mud and eight parts by weight of modified ceramic waste were added to 30 parts by weight of deionized water. The mixture was then dispersed using an ultrasonic dispersion process at 600W for 30 minutes. Ammonia was added to adjust the pH to 9, and the mixture was then stirred at 30°C for 12 hours. The resulting mixed slurry was centrifuged to obtain a solid precipitate. The solid precipitate was then dried in a 110°C oven for 2 hours, then sintered at 1000°C for 70 minutes. After sintering, the mixture was naturally cooled to room temperature to produce a ceramic-based composite material.

[0029] Comparative Example 3: A red mud-modified ceramic-based composite material specifically includes the following processes: The γ-aminopropyltriethoxysilane in Example 3 was replaced by p-aminophenyltrimethoxysilane, and the rest of the preparation process was consistent with Example 3.

[0030] Comparative Example 4: A red mud-modified ceramic-based composite material specifically includes the following processes: The γ-aminopropyltriethoxysilane in Example 3 was replaced by vinyltriethoxysilane, and the rest of the preparation process was consistent with Example 3.

[0031] Application Example 1: The application of a red mud-modified ceramic-based composite material in concrete specifically includes the following processes: Take 20 parts by weight of Portland cement with strength grade 42.5, 35 parts by weight of river sand (obtained by screening with a square hole screen of 4.75 mm), 3 parts by weight of the ceramic matrix composite obtained in Example 1, 9 parts by weight of water and 0.6 parts by weight of an air entraining agent composition (obtained by mixing sodium dodecyl sulfonate, sodium lignosulfonate and polyether defoamer XPJ890 in a weight ratio of 1:1:0.5) together into a mixer and stir for 3 min to obtain concrete.

[0032] Application Example 2: An application of a red mud modified ceramic matrix composite in concrete, specifically comprising the following processes: Take 21 parts by weight of Portland cement with strength grade 42.5, 36 parts by weight of river sand (obtained by screening with a square hole screen of 4.75 mm), 4 parts by weight of the ceramic matrix composite obtained in Example 2, 10 parts by weight of water and 0.7 parts by weight of an air entraining agent composition (obtained by mixing sodium dodecyl sulfonate, sodium lignosulfonate and polyether defoamer XPJ890 in a weight ratio of 1:1:0.5) together into a mixer and stir for 3 min to obtain concrete.

[0033] Application Example 3: An application of a red mud modified ceramic matrix composite in concrete, specifically comprising the following processes: Take 22 parts by weight of Portland cement with strength grade 42.5, 37 parts by weight of river sand (obtained by screening with a square hole screen of 4.75 mm), 5 parts by weight of the ceramic matrix composite obtained in Example 3, 10 parts by weight of water and 0.8 parts by weight of an air entraining agent composition (obtained by mixing sodium dodecyl sulfonate, sodium lignosulfonate and polyether defoamer XPJ890 in a weight ratio of 1:1:0.5) together into a mixer and stir for 3 min to obtain concrete.

[0034] Application Example 4: An application of a red mud modified ceramic matrix composite in concrete, specifically comprising the following processes: Take 22 parts by weight of Portland cement with strength grade 42.5, 37 parts by weight of river sand (obtained by screening with a square hole screen of 4.75 mm), 5 parts by weight of the ceramic matrix composite obtained in Example 3, 10 parts by weight of water and 0.8 parts by weight of an air entraining agent composition (obtained by mixing sodium dodecyl sulfonate, sodium lignosulfonate and polyether defoamer XPJ890 in a weight ratio of 1:1:0.5) together into a mixer and stir for 3 min to obtain concrete.

[0035] Application Example 5: An application of a red mud modified ceramic matrix composite in concrete, specifically comprising the following processes: Take 22 parts by weight of Portland cement with strength grade of 42.5, 37 parts by weight of river sand (obtained by screening with a square hole screen of 4.75 mm), 5 parts by weight of the ceramic matrix composite obtained in Comparative Example 2, 10 parts by weight of water and 0.8 parts by weight of an air entraining agent composition (obtained by mixing sodium dodecyl sulfonate, sodium lignin sulfonate and polyether defoaming agent XPJ890 in a weight ratio of 1:1:0.5) into a mixer and stir for 3 min to obtain concrete.

[0036] Application Example 6: An application of a red mud modified ceramic matrix composite in concrete, specifically comprising the following processes: Take 22 parts by weight of Portland cement with strength grade of 42.5, 37 parts by weight of river sand (obtained by screening with a square hole screen of 4.75 mm), 5 parts by weight of the ceramic matrix composite obtained in Comparative Example 3, 10 parts by weight of water and 0.8 parts by weight of an air entraining agent composition (obtained by mixing sodium dodecyl sulfonate, sodium lignin sulfonate and polyether defoaming agent XPJ890 in a weight ratio of 1:1:0.5) into a mixer and stir for 3 min to obtain concrete.

[0037] Application Example 7: An application of a red mud modified ceramic matrix composite in concrete, specifically comprising the following processes: Take 22 parts by weight of Portland cement with strength grade of 42.5, 37 parts by weight of river sand (obtained by screening with a square hole screen of 4.75 mm), 5 parts by weight of the ceramic matrix composite obtained in Comparative Example 4, 10 parts by weight of water and 0.8 parts by weight of an air entraining agent composition (obtained by mixing sodium dodecyl sulfonate, sodium lignin sulfonate and polyether defoaming agent XPJ890 in a weight ratio of 1:1:0.5) into a mixer and stir for 3 min to obtain concrete.

[0038] Application Example 8: An application of a red mud modified ceramic matrix composite in concrete, specifically comprising the following processes: Take 22 parts by weight of Portland cement with strength grade of 42.5, 37 parts by weight of river sand (obtained by screening with a square hole screen of 4.75 mm), 5 parts by weight of the ceramic matrix composite obtained in Example 3, 10 parts by weight of water and 0.8 parts by weight of an air entraining agent composition (obtained by mixing sodium dodecyl sulfonate and sodium lignin sulfonate in a weight ratio of 1:1) into a mixer and stir for 3 min to obtain concrete.

[0039] Application Example 9: An application of a red mud modified ceramic matrix composite in concrete, specifically comprising the following processes: Take 22 parts by weight of Portland cement with a strength grade of 42.5, 37 parts by weight of river sand (obtained by sieving through a square hole sieve of 4.75 mm), 5 parts by weight of the ceramic-based composite material obtained in Example 3, 10 parts by weight of water, and 1.2 parts by weight of an air-entraining agent composition (obtained by mixing sodium dodecyl sulfonate, sodium lignosulfonate, and polyether defoaming agent XPJ890 in a weight ratio of 1:1:0.5) into a blender and stir for 3 min to obtain concrete.

[0040] The concrete obtained in Application Examples 1 to 9 was poured into a mold, and after molding for 24 h, it was placed in water at 20℃ for curing for 3 days, and then the compressive strength was tested in accordance with the standard GB / T 50081-2019 Test Methods for Physical and Mechanical Properties of Concrete, and the results are shown in Table 1 below.

[0041] Table 1 Mechanical properties

[0042] Porosity test: The concrete cured according to the above curing method was placed in a drying oven set at 105℃ to dry and remove water until the weight no longer changed, cooled to room temperature, and the volume V was measured and calculated; the dried concrete was completely immersed in water, and when there was no bubbling, the mass m1 in water was measured; the water-absorbed concrete was taken out and placed in an electric heating air drying oven at 70℃ for 24 h, and the mass m2 was measured; the porosity = [1-(m2-m1) / V] x 100%, and the results are shown in Table 2 below.

[0043] Table 2 Porosity

[0044] From the above Tables 1 and 2, the following conclusions can be drawn: (1) From Application Examples 1 to 3, it can be found that the ceramic-based composite material prepared by the present application not only has good porosity, but also has good mechanical properties when prepared into concrete.

[0045] (2) From Application Example 4, it can be found that the mechanical properties of the prepared concrete are poor, which may be due to the fact that in this system, when the particle size is further reduced, the specific surface area increases, and the dispersion of the modified silane coupling agent is poor, which may lead to increased shrinkage after hydration, and thus easily leading to tensile stress inside the concrete, causing surface or internal cracks, and weakening the mechanical properties.

[0046] (3) Through application example 5, it can be found that the mechanical properties of the prepared concrete are poor, which may be due to the fact that in the present system, if levodopa and gamma-aminopropyl triethoxysilane are reacted in an acidic environment, although the acidic environment helps to activate the carboxyl group and thus promote the occurrence of condensation reaction, the acidity can cause the hydrolysis and self-condensation of gamma-aminopropyl triethoxysilane, which may weaken the surface modification of ceramic waste and red mud particles and is not conducive to the dispersion of ceramic waste and red mud particles, thereby possibly leading to the decrease of the mechanical properties of the concrete and being not conducive to use.

[0047] (4) Through application example 6, it can be found that the mechanical properties of the prepared concrete are poor and the porosity is low, which may be due to the fact that in the present system, although the aminophenyl trimethoxysilane contains an amino group, due to the influence of the rigid structure of the benzene ring, the pore structure is formed poorly and the porosity is low, and the improvement effect of the air entraining agent composition on the preparation process of the concrete may be weakened, leading to poor mechanical properties.

[0048] (5) Through application example 7, it can be found that the mechanical properties of the prepared concrete are poor, which may be due to the fact that in the present system, although vinyl triethoxysilane can realize the surface modification of red mud particles and ceramic waste at high temperature, since vinyl triethoxysilane does not contain an amino group, it cannot be condensed with levodopa, which may lead to poor interfacial adhesion when the modified red mud and the modified ceramic waste are mixed and reacted, thereby leading to poor mechanical properties.

[0049] (6) Through application example 8, it can be found that the mechanical properties of the prepared concrete are poor, which may be due to the fact that in the present system, the sodium dodecyl sulfonate and the sodium lignosulfonate used have strong foaming properties and too much foam, which leads to high air content of the concrete and weakens the mechanical properties of the concrete.

[0050] (7) Through application example 9, it can be found that the mechanical properties of the prepared concrete are poor, which may be due to the fact that in the present system, although the addition of the air entraining agent composition can improve the pore structure of the concrete, when too much air entraining agent composition is used, the slurry is prone to become thin, which in turn weakens the mechanical properties of the concrete.

[0051] The above examples have described the technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A red mud modified ceramic matrix composite material, characterized in that: The preparation method of the ceramic matrix composite material comprises the following steps: Levodopa, a silane coupling agent, EDC hydrochloride and N-hydroxysuccinimide are mixed and reacted in a molar ratio of 1:0.8-1:2-3:2.5-3.5 to obtain a modified silane coupling agent; The modified silane coupling agent and red mud particles are mixed in a weight ratio of 1:70-80 to obtain modified red mud; The modified silane coupling agent and the ceramic waste are mixed in a weight ratio of 1:50-60 to obtain the modified ceramic waste; Modified red mud, modified ceramic waste and water are mixed in a weight ratio of 1:6-8:20-30 to obtain a mixed slurry. The mixed slurry is centrifuged, dried and dehydrated, and then sintered at a high temperature to obtain a ceramic-based composite material.

2. The red mud-modified ceramic matrix composite material according to claim 1, characterized in that: The silane coupling agent includes γ-aminopropyltrimethoxysilane or γ-aminopropyltriethoxysilane.

3. The red mud-modified ceramic-based composite material according to claim 1, characterized in that: The conditions for the mixed reaction of levodopa, silane coupling agent, EDC hydrochloride and N-hydroxysuccinimide include a reaction temperature of 30° C. to 35° C. and a reaction time of 5 h to 7 h.

4. The red mud-modified ceramic-based composite material according to claim 1, characterized in that: The conditions for the mixed reaction of the modified silane coupling agent and the red mud particles include a reaction temperature of 110° C. to 120° C. and a reaction time of 40 min to 60 min.

5. The red mud-modified ceramic-based composite material according to claim 1, characterized in that: The conditions for the mixed reaction of the modified silane coupling agent and the ceramic waste include a reaction temperature of 80° C. to 90° C. and a reaction time of 3 h to 4 h.

6. The red mud-modified ceramic matrix composite material according to claim 1, characterized in that: The conditions for the mixed reaction of the modified red mud, the modified ceramic waste and water include a reaction pH value of 8.5-9, a reaction temperature of 25° C.-30° C. and a reaction time of 10 h-12 h.

7. Use of a red mud-modified ceramic-based composite material according to any one of claims 1 to 6 in concrete, characterized in that: The application comprises the following steps: Cement, river sand, ceramic-based composite material, water and air-entraining agent composition are mixed and stirred in a weight ratio of 20-22:35-37:3-5:9-10:0.6-0.8 to obtain concrete.

8. The use of a red mud-modified ceramic-based composite material in concrete according to claim 7, characterized in that: The cement is silicate cement with a strength grade of 42.

5.

9. The use of a red mud-modified ceramic-based composite material in concrete according to claim 7, characterized in that: The air entraining agent composition is composed of sodium dodecyl sulfonate, sodium lignin sulfonate and polyether defoamer XPJ890 in a weight ratio of 1:1:0.5.

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