Environment-friendly lightweight aggregate ecological concrete and preparation method thereof

Abstract

The invention discloses environment-friendly lightweight aggregate ecological concrete and a preparation method thereof, and belongs to the technical field of novel environment-friendly building materials, the waterproof performance of the concrete is enhanced through inorganic modification treatment of corncob particles, and the concrete is mixed with cement, fly ash, environment-friendly sand, ceramsite and the like to form dry-mixed powder. Adding a functional agent and water, stirring, and filling into a mold for curing and forming. Compared with the prior art, the concrete has excellent mechanical properties, high porosity and good water-retaining property, is suitable for the fields of buildings and engineering, effectively supports plant growth and promotes ecological restoration, and is a novel green building material.

Description

Technical Field

[0001] The invention relates to the technical field of new green building materials, and in particular to an environmentally friendly light aggregate ecological concrete and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization and the continuous expansion of infrastructure construction, concrete, as one of the main building materials, has been widely used in buildings, roads, bridges and other fields. However, there are some problems that cannot be ignored in traditional concrete, such as high energy consumption, high carbon emissions, ecological damage and negative impact on the environment. These problems have prompted the building materials industry to seek new materials that are more environmentally friendly and sustainable.

[0003] Lightweight aggregate concrete is a building material developed by incorporating lightweight aggregates into traditional concrete mixtures. This material was developed to address the limitations of traditional concrete in certain applications, especially in situations where it is necessary to reduce the deadweight of the structure and improve thermal and sound insulation performance. The preparation of lightweight aggregate concrete usually uses ceramsite, polyurethane, etc. as filling lightweight aggregates. These aggregates can significantly reduce the overall density of concrete due to their low density characteristics, and therefore show wide application potential in the field of civil engineering. However, existing lightweight concrete materials do not make sufficient resource utilization of agricultural solid waste and abandoned construction waste. The raw materials used are mostly traditional cement and natural sand and gravel. In addition, a large number of corn cobs are burned or piled up in rural areas, and the problem of construction waste stacking is increasing in cities, which seriously pollutes the environment and causes waste of resources, and urgently needs to be improved and utilized.

[0004] As a new type of green building material, ecological concrete has attracted attention due to its excellent ecological functions and environmental friendliness. It can not only reduce the consumption of natural resources, but also improve the ecological environment and promote vegetation recovery. Although ecological concrete has obvious advantages in environmental protection, its mechanical properties and durability are often inferior to traditional concrete, especially in terms of compressive strength and porosity, which limits its application in a wider range of fields.

[0005] In addition, traditional eco-concrete often requires a large amount of cement during its preparation, which not only increases costs but also increases the carbon footprint of concrete. At the same time, traditional eco-concrete has insufficient water retention, which is not conducive to the growth and maintenance of vegetation, limiting its application in the field of ecological restoration.

[0006] Chinese invention patent CN115650664A discloses a multifunctional environmentally friendly ecological concrete and its preparation method. The concrete includes the following raw materials by mass: 50-180 parts of cement, 30-110 parts of saw mud, 30-110 parts of modified sepiolite powder, 900-1500 parts of phosphogypsum coarse aggregate, 5-10 parts of water reducer, 70-170 parts of water, 3-8 parts of potassium polyacrylate, 4-9 parts of polyvinyl acetate emulsion, and 3-6 parts of 2-methyl-2,4-pentanediol solution. The invention rationally utilizes solid wastes such as saw mud and phosphogypsum, and the prepared concrete not only has excellent strength, toughness, shrinkage resistance and other properties, but also has adsorption, purification, water permeability and temperature and humidity regulation functions, which can be applied to many application scenarios. However, the compressive strength and porosity of the ecological concrete prepared by the invention are insufficient, which is not conducive to vegetation growth. Summary of the invention

[0007] In view of the above problems, the present invention aims to develop an environmentally friendly lightweight aggregate ecological concrete and a preparation method thereof, so as to improve the mechanical properties and ecological functions of concrete while reducing its environmental impact.

[0008] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions: A method for preparing environmentally friendly lightweight aggregate ecological concrete is as follows: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; Step 2: Add cement, fly ash, environmentally friendly sand, coarse ceramsite and fine ceramsite into a mixer and stir for 2 to 3 minutes to fully mix and obtain dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2 and the waterproof corn cob particles prepared in step 1, add water and stir, put the mixture into a mold, and cure and shape it to obtain environmentally friendly lightweight aggregate ecological concrete.

[0009] The environmentally friendly lightweight aggregate ecological concrete is prepared from the following raw materials in parts by weight: 100-250 parts of cement, 100-250 parts of fly ash, 700-800 parts of environmentally friendly sand, 100-150 parts of fine ceramsite, 20-50 parts of coarse ceramsite, 1-3 parts of liquid waterproofing agent, 5-30 parts of corn cob particles, and 250-280 parts of water.

[0010] Preferably, the preparation method of the environmentally friendly lightweight aggregate ecological concrete is as follows: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; Step 2: Add cement, fly ash, environmentally friendly sand, coarse ceramsite and fine ceramsite into a mixer and stir for 2 to 3 minutes to fully mix and obtain dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2, the functional agent and the waterproof corn cob particles prepared in step 1, add water and stir, put the mixture into a mold, and cure and shape it to obtain environmentally friendly lightweight aggregate ecological concrete.

[0011] Preferably, the environmentally friendly lightweight aggregate ecological concrete is prepared from the following raw materials in parts by weight: 100-250 parts of cement, 100-250 parts of fly ash, 700-800 parts of environmentally friendly sand, 100-150 parts of fine ceramsite, 20-50 parts of coarse ceramsite, 1-3 parts of liquid waterproofing agent, 8-12 parts of functional agent, 5-30 parts of corn cob particles, and 250-280 parts of water.

[0012] The preparation method of the functional agent is as follows: S1, adding nonylphenol polyoxyethylene ether to dimethylformamide to obtain solution A, adding dimethyltriphenylmethane tetraisocyanate to dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them in a high temperature environment to obtain a pretreated material; adding arabinoxylan to 1-allyl-1H-imidazole-2-amine, and stirring at high temperature and nitrogen protection conditions to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at high temperature. After the mixture is cooled to room temperature, water is added for precipitation treatment, followed by filtration and freeze-drying to obtain a functional agent.

[0013] The inorganic modification treatment is: using a liquid waterproofing agent to waterproof the corn cob particles to obtain waterproof corn cob particles with a moist surface, and then putting them into an oven at a temperature of 100-110° C. for drying to obtain waterproof corn cob particles.

[0014] Preferably, the liquid waterproofing agent is a silicone waterproofing agent.

[0015] The average particle size of the fine ceramsite is 4-8 mm.

[0016] The cement is at least one of sulphoaluminate cement and ordinary Portland cement.

[0017] The average particle size of the coarse ceramsite is 10-15 mm.

[0018] The curing and molding is carried out under the conditions of 92-98% relative humidity and 18-22° C.

[0019] Preferably, the preparation method of the functional agent is as follows, in parts by weight: S1. Add 1-3 parts of nonylphenol polyoxyethylene ether to 15-25 parts of dimethylformamide to obtain solution A, add 8-12 parts of dimethyltriphenylmethane tetraisocyanate to 80-120 parts of dimethylformamide to obtain solution B, mix solution A and solution B, and treat them in an environment of 50-70° C. for 5-20 hours to obtain a pretreated product; add 3-5 parts of arabinoxylan to 30-50 parts of 1-allyl-1H-imidazole-2-amine, and stir them at 30-45° C. under nitrogen protection for 1-5 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1, and treat at 60-80°C for 10-20 hours. After the mixture is cooled to room temperature, add 150-250 parts of water for precipitation treatment 1-3 times, and then filter and freeze-dry to obtain a functional agent.

[0020] The functions of the various substances described in the present invention are as follows: Sulphoaluminate cement serves as the primary binder of concrete, providing strength and stability.

[0021] Corncob particles, as a kind of lightweight aggregate, have waterproof properties after inorganic modification, which helps to improve the lightness and thermal insulation of concrete while reducing the impact on the environment.

[0022] Liquid waterproofing agent is used to treat corncob particles to form a waterproof layer on their surface, enhancing the waterproof performance of the particles, thereby improving the durability and impermeability of concrete.

[0023] Cement, as the main bonding material of concrete, provides strength and stability and ensures the structural strength of concrete.

[0024] As a substitute or supplement to cement, fly ash can improve the workability and durability of concrete while reducing cement usage and costs.

[0025] Environmentally friendly sand acts as fine aggregate to fill and shape concrete, improving the fluidity and workability of concrete.

[0026] Coarse expanded clay and fine expanded clay are used as lightweight aggregates to reduce the density of concrete, improve the thermal and sound insulation properties of concrete, and increase the compressive strength of concrete.

[0027] Water is an essential ingredient for concrete mixing and hydration reactions.

[0028] The functional agent in the present invention realizes that the polymer water-retaining material stores a large amount of water in the long molecular chain through the method of grafting modification, and absorbs and retains water when the environmental moisture is sufficient. Specifically, the preparation of the functional agent involves dissolving nonylphenol polyoxyethylene ether and dimethyl triphenylmethane tetraisocyanate in dimethylformamide and then mixing them, forming a pre-treated product through polymerization reaction, and then adding this pre-treated product to arabinoxylan dissolved in 1-allyl-1H-imidazole-2-amine, reacting at a certain temperature, and finally obtaining the functional agent through precipitation, filtration, washing and freeze drying. The introduction of arabinoxylan increases the pore structure of the material, improves its porosity and permeability, so that the material can absorb water when the environmental moisture is sufficient while retaining moisture, effectively avoiding the problem of excessive hardening of ecological concrete, thereby improving the performance and application effect of ecological concrete.

[0029] As a component of the functional agent, arabinoxylan improves the water absorption and retention properties of concrete.

[0030] 1-allyl-1H-imidazole-2-amine, as a component of the functional agent, participates in forming the chemical structure of the functional agent and improves the ecological performance of concrete.

[0031] Dimethyltriphenylmethane tetraisocyanate is used as a component of the functional agent for grafting modification to enhance the performance of the functional agent.

[0032] The combination and interaction of these substances make the environmentally friendly lightweight aggregate ecological concrete of the present invention not only have excellent mechanical properties, but also have good ecological functions, such as water retention, air permeability and plant growth support ability.

[0033] Compared with the prior art, it has the following beneficial effects: 1) The present invention realizes the waterproof function of corncob particles, improves the water and slurry absorption effect of corncobs, effectively controls the water-binder ratio of composite lightweight aggregate concrete, and helps to ensure the strength of lightweight aggregate concrete.

[0034] 2) Corn cobs are agricultural waste, and environmentally friendly sand is construction waste. The present invention realizes the utilization of solid waste in rural and urban areas, which can reduce construction costs, improve the environment in rural and urban areas, and provide guidance for the preparation and use of new environmentally friendly building materials.

[0035] 3) The packing density of corn cobs, environmentally friendly sand and expanded clay can be kept stable by matching the particle size; the mixing of coarse and fine aggregates with matching particle size and inorganic cementitious materials can significantly stabilize the apparent dry density of lightweight aggregate concrete.

[0036] 4) The flame retardant function of corn cobs is realized, the flammable properties of the material itself are changed, and the potential safety hazards in the construction process of light aggregate are significantly eliminated, making the light aggregate a Class A safe flame retardant product.

[0037] 5) The present invention improves the water retention capacity and porosity of ecological concrete by introducing functional agents, especially using arabinoxylan and specific isocyanates, thereby enhancing the ecological function and environmental adaptability of concrete. This improvement helps the growth and water retention of plant roots, and has a positive effect on the restoration of vegetation coverage and ecological environment.

[0038] 6) The environmentally friendly lightweight aggregate ecological concrete of the present invention exhibits higher compressive strength by optimizing the material ratio and the preparation method of the functional agent. This enhanced mechanical property enables the ecological concrete to have sufficient structural strength while maintaining a lightweight and high-porosity structure, making it suitable for more construction and engineering applications.

[0039] 7) The ecological concrete of the present invention provides more favorable conditions for plant growth due to its good water retention and pore structure. The concrete of the present invention can more effectively support plant growth, help achieve the goals of greening and ecological restoration, and improve the quality of urban landscape and ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart for preparing environmentally friendly lightweight aggregate ecological concrete according to Example 4 of the present invention. DETAILED DESCRIPTION

[0041] Main sources of substances: Sulphoaluminate cement, cement fineness: 360%, initial setting time: 0.5h, compressive strength: 50-80MPa, brand: Leiante.

[0042] Silicone waterproofing agent, use: for mortar, concrete, product number: FSJ001, brand: POWNICE / Pulis.

[0043] Corn cob particles, particle size: 4~6mm.

[0044] Fly ash, product specifications: first-grade ash 325 mesh, Lingshou County Yaoxin Mineral Products Processing Plant.

[0045] Environmentally friendly sand is made by artificially crushing waste concrete, sieving it into 15~30mm, and then washing and drying it.

[0046] The average particle size of coarse expanded clay is 10~15mm.

[0047] The average particle size of fine ceramsite is 4~8mm.

[0048] Organic nutrient soil, organic matter ≥ 30%, total nutrients (N+P 2 O 5 +K 2 0) ≥4.0%, main raw materials: chicken manure residue, edible fungus residue, straw.

[0049] Perlite, specification: 3~5mm.

[0050] Coconut shell fiber, length: 300mm.

[0051] Phosphogypsum, product specifications: 325 mesh.

[0052] Peat soil, item number: 12, PH value: 7, Lingshou County Kaixin Mineral Products Processing Plant.

[0053] Arabinoxylan, product number: TB04677, Hubei Tuobang Chemical Co., Ltd.

[0054] Mannan, product number: S51698, Shanghai Yuanye Biotechnology Co., Ltd.

[0055] Xyloglucan, product number: XHL2216, Hubei Xinhongli Chemical Co., Ltd.

[0056] Dimethyltriphenylmethane tetraisocyanate, CAS number: 28886-07-9.

[0057] The remaining raw materials in the examples and comparative examples of the present invention are all commercially available products.

[0058] The design idea of ​​the present invention is to use environmentally friendly lightweight aggregate ecological concrete as a new type of green building material, and to achieve the environmental protection, lightness, high porosity and good water retention of concrete through precise proportioning and innovative preparation methods. Specifically, the present invention mixes raw materials such as sulphoaluminate cement, carboxymethyl cellulose, polycarboxylic acid water reducer, film-forming aid and functional agent, and adds coarse aggregate, sepiolite powder, organic nutrient soil, perlite and kaolin, etc., and prepares ecological concrete that has excellent mechanical properties and can promote vegetation growth through the steps of uniform stirring, mold filling and curing and forming. Functional agent is a polymer material with good water absorption and water retention, thereby improving the ecological function and environmental adaptability of concrete. Example 1

[0059] A method for preparing environmentally friendly lightweight aggregate ecological concrete is as follows: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; the inorganic modification treatment is: using 1.5 parts by weight of an organic silicon waterproofing agent to perform waterproof treatment on 25 parts by weight of corn cob particles to obtain waterproof corn cob particles with a moist surface, and then placing the corn cob particles in an oven at a temperature of 105° C. for drying to obtain waterproof corn cob particles; Step 2: Add 100 parts by weight of sulphoaluminate cement, 250 parts by weight of fly ash, 727 parts by weight of environmentally friendly sand, 30 parts by weight of coarse ceramsite, and 133 parts by weight of fine ceramsite into a mixer and stir for 2 minutes to fully mix and obtain a dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2 and the waterproof corn cob particles prepared in step 1, add 280 parts by weight of water and stir, put the mixture into a mold, and cure it under a relative humidity of 95% and a temperature of 20°C to obtain environmentally friendly lightweight aggregate ecological concrete. Example 2

[0060] A method for preparing environmentally friendly lightweight aggregate ecological concrete is as follows: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; the inorganic modification treatment is: using 1.5 parts by weight of an organic silicon waterproofing agent to perform waterproof treatment on 25 parts by weight of corn cob particles to obtain waterproof corn cob particles with a moist surface, and then placing the corn cob particles in an oven at a temperature of 105° C. for drying to obtain waterproof corn cob particles; Step 2: Add 150 parts by weight of sulphoaluminate cement, 200 parts by weight of fly ash, 727 parts by weight of environmentally friendly sand, 30 parts by weight of coarse ceramsite, and 133 parts by weight of fine ceramsite into a mixer and stir for 2 minutes to fully mix and obtain a dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2 and the waterproof corn cob particles prepared in step 1, add 280 parts by weight of water and stir, put the mixture into a mold, and cure it under a relative humidity of 95% and a temperature of 20°C to obtain environmentally friendly lightweight aggregate ecological concrete. Example 3

[0061] A method for preparing environmentally friendly lightweight aggregate ecological concrete is as follows: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; the inorganic modification treatment is: using 1.5 parts by weight of an organic silicon waterproofing agent to perform waterproof treatment on 25 parts by weight of corn cob particles to obtain waterproof corn cob particles with a moist surface, and then placing the corn cob particles in an oven at a temperature of 105° C. for drying to obtain waterproof corn cob particles; Step 2: Add 200 parts by weight of sulphoaluminate cement, 150 parts by weight of fly ash, 727 parts by weight of environmentally friendly sand, 30 parts by weight of coarse ceramsite, and 133 parts by weight of fine ceramsite into a mixer and stir for 2 minutes to fully mix and obtain a dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2 and the waterproof corn cob particles prepared in step 1, add 280 parts by weight of water and stir, put the mixture into a mold, and cure it under a relative humidity of 95% and a temperature of 20°C to obtain environmentally friendly lightweight aggregate ecological concrete. Example 4

[0062] A method for preparing environmentally friendly lightweight aggregate ecological concrete is as follows: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; the inorganic modification treatment is: using 1.5 parts by weight of an organic silicon waterproofing agent to perform waterproof treatment on 25 parts by weight of corn cob particles to obtain waterproof corn cob particles with a moist surface, and then placing the corn cob particles in an oven at a temperature of 105° C. for drying to obtain waterproof corn cob particles; Step 2: Add 250 parts by weight of sulphoaluminate cement, 100 parts by weight of fly ash, 727 parts by weight of environmentally friendly sand, 30 parts by weight of coarse ceramsite, and 133 parts by weight of fine ceramsite into a mixer and stir for 2 minutes to fully mix and obtain a dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2 and the waterproof corn cob particles prepared in step 1, add 280 parts by weight of water and stir, put the mixture into a mold, and cure it under a relative humidity of 95% and a temperature of 20°C to obtain environmentally friendly lightweight aggregate ecological concrete. Example 5

[0063] A method for preparing environmentally friendly lightweight aggregate ecological concrete is as follows: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; the inorganic modification treatment is: using 1.5 parts by weight of an organic silicon waterproofing agent to perform waterproof treatment on 25 parts by weight of corn cob particles to obtain waterproof corn cob particles with a moist surface, and then placing the corn cob particles in an oven at a temperature of 105° C. for drying to obtain waterproof corn cob particles; Step 2: Add 250 parts by weight of sulphoaluminate cement, 100 parts by weight of fly ash, 727 parts by weight of environmentally friendly sand, 30 parts by weight of coarse ceramsite, and 133 parts by weight of fine ceramsite into a mixer and stir for 2 minutes to fully mix and obtain a dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2, 10 parts by weight of the functional agent and the waterproof corn cob particles prepared in step 1, add 280 parts by weight of water and stir, put the mixture into a mold, and cure it under a relative humidity of 95% and a temperature of 20°C to obtain environmentally friendly lightweight aggregate ecological concrete.

[0064] The preparation method of the functional agent is as follows: S1, adding 2kg of nonylphenol polyoxyethylene ether to 20kg of dimethylformamide to obtain solution A, adding 10kg of dimethyltriphenylmethane tetraisocyanate to 100kg of dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them at 60°C for 12 hours to obtain a pretreated material; adding 4kg of arabinoxylan to 40kg of 1-allyl-1H-imidazole-2-amine, and stirring them at 40°C under nitrogen protection for 4 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at 70° C. for 12 hours. After the mixture is cooled to room temperature, add 200 kg of water for precipitation treatment three times, and then filter and freeze-dry to obtain a functional agent. Example 6

[0065] The preparation method of an environmentally friendly lightweight aggregate ecological concrete is basically the same as that of Example 5, the only difference being that the preparation method of the functional agent is different.

[0066] The preparation method of the functional agent is as follows: S1, adding 2kg of nonylphenol polyoxyethylene ether to 20kg of dimethylformamide to obtain solution A, adding 10kg of 4,4ˊ,4〞-triphenylmethane triisocyanate to 100kg of dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them at 60°C for 12 hours to obtain a pretreated material; adding 4kg of arabinoxylan to 40kg of 1-allyl-1H-imidazole-2-amine, and stirring them at 40°C under nitrogen protection for 4 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at 70° C. for 12 hours. After the mixture is cooled to room temperature, add 200 kg of water for precipitation treatment three times, and then filter and freeze-dry to obtain a functional agent. Example 7

[0067] The preparation method of an environmentally friendly lightweight aggregate ecological concrete is basically the same as that of Example 5, the only difference being that the preparation method of the functional agent is different.

[0068] The preparation method of the functional agent is as follows: S1. Add 2 kg of nonylphenol polyoxyethylene ether to 20 kg of dimethylformamide to obtain solution A, add 10 kg of 4,4'-methylenebis(phenyl isocyanate) to 100 kg of dimethylformamide to obtain solution B, mix solution A and solution B, and treat them at 60° C. for 12 hours to obtain a pretreated product; add 4 kg of arabinoxylan to 40 kg of 1-allyl-1H-imidazole-2-amine, and stir at 40° C. under nitrogen protection for 4 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at 70° C. for 12 hours. After the mixture is cooled to room temperature, add 200 kg of water for precipitation treatment three times, and then filter and freeze-dry to obtain a functional agent. Example 8

[0069] The preparation method of an environmentally friendly lightweight aggregate ecological concrete is basically the same as that of Example 5, the only difference being that the preparation method of the functional agent is different.

[0070] The preparation method of the functional agent is as follows: S1, adding 2kg of nonylphenol polyoxyethylene ether to 20kg of dimethylformamide to obtain solution A, adding 10kg of dimethyltriphenylmethane tetraisocyanate to 100kg of dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them at 60°C for 12 hours to obtain a pretreated material; adding 4kg of mannan to 40kg of 1-allyl-1H-imidazole-2-amine, and stirring them at 40°C under nitrogen protection for 4 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at 70° C. for 12 hours. After the mixture is cooled to room temperature, add 200 kg of water for precipitation treatment three times, and then filter and freeze-dry to obtain a functional agent. Example 9

[0071] The preparation method of an environmentally friendly lightweight aggregate ecological concrete is basically the same as that of Example 5, the only difference being that the preparation method of the functional agent is different.

[0072] The preparation method of the functional agent is as follows: S1, adding 2kg of nonylphenol polyoxyethylene ether to 20kg of dimethylformamide to obtain solution A, adding 10kg of dimethyltriphenylmethane tetraisocyanate to 100kg of dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them in an environment of 60° C. for 12 hours to obtain a pretreated material; adding 4kg of mannan to 40kg of 1-allyl-3-vinyl imidazole chloride, and stirring them at 40° C. under nitrogen protection for 4 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at 70° C. for 12 hours. After the mixture is cooled to room temperature, add 200 kg of water for precipitation treatment three times, and then filter and freeze-dry to obtain a functional agent.

[0073] Comparative Example 1 The preparation method of an environmentally friendly lightweight aggregate ecological concrete is basically the same as that of Example 5, the only difference being that the preparation method of the functional agent is different.

[0074] The preparation method of the functional agent is as follows: S1, adding 2kg of nonylphenol polyoxyethylene ether to 20kg of dimethylformamide to obtain solution A, adding 10kg of 3-ethylphenyl isocyanate to 100kg of dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them at 60°C for 12 hours to obtain a pretreated material; adding 4kg of arabinoxylan to 40kg of 1-allyl-1H-imidazole-2-amine, and stirring them at 40°C under nitrogen protection for 4 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at 70° C. for 12 hours. After the mixture is cooled to room temperature, add 200 kg of water for precipitation treatment three times, and then filter and freeze-dry to obtain a functional agent.

[0075] Comparative Example 2 The preparation method of an environmentally friendly lightweight aggregate ecological concrete is basically the same as that of Example 5, the only difference being that the preparation method of the functional agent is different.

[0076] The preparation method of the functional agent is as follows: S1, adding 2kg of nonylphenol polyoxyethylene ether to 20kg of dimethylformamide to obtain solution A, adding 10kg of dimethyltriphenylmethane tetraisocyanate to 100kg of dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them at 60°C for 12 hours to obtain a pretreated material; adding 4kg of xyloglucan to 40kg of 1-allyl-1H-imidazole-2-amine, and stirring them at 40°C under nitrogen protection for 4 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at 70° C. for 12 hours. After the mixture is cooled to room temperature, add 200 kg of water for precipitation treatment three times, and then filter and freeze-dry to obtain a functional agent.

[0077] Comparative Example 3 The preparation method of an environmentally friendly lightweight aggregate ecological concrete is basically the same as that of Example 5, the only difference being that the preparation method of the functional agent is different.

[0078] The preparation method of the functional agent is as follows: S1, adding 2kg of nonylphenol polyoxyethylene ether to 20kg of dimethylformamide to obtain solution A, adding 10kg of dimethyltriphenylmethane tetraisocyanate to 100kg of dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them at 60°C for 12 hours to obtain a pretreated product; adding 4kg of arabinoxylan to 40kg of N-allylimidazole, and stirring them at 40°C under nitrogen protection for 4 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at 70° C. for 12 hours. After the mixture is cooled to room temperature, add 200 kg of water for precipitation treatment three times, and then filter and freeze-dry to obtain a functional agent.

[0079] Comparative Example 4 A method for preparing environmentally friendly lightweight aggregate ecological concrete is as follows: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; the inorganic modification treatment is: using 1.5 parts by weight of an organic silicon waterproofing agent to perform waterproof treatment on 25 parts by weight of corn cob particles to obtain waterproof corn cob particles with a moist surface, and then placing the corn cob particles in an oven at a temperature of 105° C. for drying to obtain waterproof corn cob particles; Step 2: Add 250 parts by weight of sulphoaluminate cement, 100 parts by weight of fly ash, 727 parts by weight of environmentally friendly sand, 30 parts by weight of coarse ceramsite, and 133 parts by weight of fine ceramsite into a mixer and stir for 2 minutes to fully mix and obtain a dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2, 10 parts by weight of arabinoxylan and the waterproof corn cob particles prepared in step 1, add 280 parts by weight of water and stir, put the mixture into a mold, and cure it under a relative humidity of 95% and a temperature of 20°C to obtain environmentally friendly lightweight aggregate ecological concrete.

[0080] Test Example 1 The strength of the environmentally friendly lightweight aggregate ecological concrete prepared by the present invention was tested with reference to the "GB / T50081-2019 Standard for Test Methods for Physical and Mechanical Properties of Concrete".

[0081] Porosity test: first measure the apparent volume V of the environmentally friendly lightweight aggregate ecological concrete prepared by the present invention, then immerse it in water and soak it at room temperature for 48 hours until there are no bubbles when shaken, and weigh its mass M suspended in water using a hydrostatic electronic balance. 1 , then take it out and drain it, weigh its mass and record it as M 2 , then the porosity = (1-(M 1 -M 2 ) / ρ 水 V) × 100%. The test results are shown in Table 1.

[0082] Table 1 Experimental protocol 28d compressive strength (MPa) Porosity(%) Example 1 7.5 23.7 Example 2 8.3 23.9 Example 3 9.3 24.0 Example 4 10.9 24.2 Example 5 12.7 31.6 Example 6 12.1 30.7 Example 7 12.3 30.9 Example 8 12.3 30.5 Example 9 12.2 30.7 Comparative Example 1 11.6 30.2 Comparative Example 2 11.7 30.1 Comparative Example 3 11.5 30.0 Comparative Example 4 10.3 27.9 Test Example 2 Vegetation coverage test After sowing grass seeds, covering the soil and watering, the environmentally friendly light aggregate ecological concrete was cultivated for 10 days. The thickness of the soil was 1.5 cm, and the mass percentage of each component in the soil was 60 wt% of organic nutrient soil, 5 wt% of coconut shell fiber, 5 wt% of fly ash, 17 wt% of phosphogypsum, 4 wt% of sodium alginate, 6 wt% of perlite, and 3 wt% of peat soil. Then the vegetation coverage rate was tested by acupuncture. For the ecological concrete in a partition frame, its shape is a square with a side length of 100 cm. The side length of the square is marked every 10 cm, and then the marks are connected in the horizontal and vertical directions using a sample rope to form an intersection. 100 intersections are randomly selected from the intersections, and a fine needle with a diameter of 2 mm is used to vertically insert from the top of the vegetation. If the fine needle contacts the root of the vegetation, "yes" is recorded, and if the fine needle does not contact the root of the vegetation, "no" is recorded, and finally the vegetation coverage rate is calculated. Vegetation coverage rate = (number of times “yes” was recorded / total number of acupuncture times) × 100%. The test results are shown in Table 2.

[0083] The test results are shown in Table 2.

[0084] Table 2 Experimental protocol Vegetation coverage (%) Example 1 66 Example 2 63 Example 3 59 Example 4 52 Example 5 94 Example 6 92 Example 7 91 Example 8 91 Example 9 90 Comparative Example 1 87 Comparative Example 2 89 Comparative Example 3 88 Comparative Example 4 78 It can be seen from the data in Tables 1 and 2 that the environmentally friendly lightweight aggregate ecological concrete prepared in Example 5 has the best effects in terms of compressive strength, porosity and vegetation coverage.

[0085] The dimethyl triphenylmethane tetraisocyanate used in Example 5 has better compressive strength, porosity and vegetation coverage than the isocyanates used in other embodiments and comparative examples. This may be due to the structural characteristics of dimethyl triphenylmethane tetraisocyanate, which can form stronger chemical bonds with components such as polyoxyethylene ether and arabinoxylan, thereby enhancing the overall performance of the functional agent. This structure may provide better cross-linking density and network structure, thereby improving the mechanical properties and water retention capacity of ecological concrete. A stronger cross-linked network helps to maintain the pore structure of concrete, thereby increasing its porosity, which is crucial for the growth and water retention of plant roots. At the same time, good water retention capacity helps to improve vegetation coverage because plants can obtain better water and nutritional conditions in this environment, thereby promoting their growth.

[0086] The arabinoxylan used in Example 5 shows better compressive strength, porosity and vegetation coverage in the preparation of environmentally friendly lightweight aggregate ecological concrete than the mannan used in Example 8 and the xyloglucan used in Comparative Example 2, which may be related to the unique structure and properties of arabinoxylan. Arabinoxylan is a complex polysaccharide whose main chain is composed of xylose and whose side chains contain monosaccharides such as arabinose. This structure gives it good water solubility and water retention capacity. In concrete, this water retention helps to maintain the moisture balance inside the concrete, thereby better maintaining the moisture required for cement hydration during the curing process, and enhancing the compressive strength and durability of the concrete. At the same time, the introduction of arabinoxylan may improve the pore structure inside the concrete, increase the porosity, and provide more growth space for plant roots, which helps to increase the vegetation coverage. In contrast, although mannan and xyloglucan also have certain water retention and structural characteristics, they may not be as effective as arabinoxylan in improving the mechanical properties and ecological functions of concrete. Therefore, the application of arabinoxylan in the present invention shows better comprehensive performance.

[0087] The 1-allyl-1H-imidazole-2-amine used in Example 5 shows better compressive strength, porosity and vegetation coverage in the preparation of environmentally friendly lightweight aggregate ecological concrete than the 1-allyl-3-vinyl imidazole chloride used in Example 9 and the N-allyl imidazole used in Comparative Example 3, which may be related to the unique chemical structure and reactivity of 1-allyl-1H-imidazole-2-amine. As an organic amine compound, the double bonds, imidazole rings and amino structures contained in 1-allyl-1H-imidazole-2-amine may provide more reaction sites and cross-linking possibilities during the synthesis of the functional agent, thereby enhancing the intermolecular forces and overall performance of the functional agent. This enhanced intermolecular force helps to improve the mechanical properties and durability of concrete. At the same time, 1-allyl-1H-imidazole-2-amine may form a more stable network structure in the functional agent, which helps to maintain the moisture inside the concrete, thereby improving the water retention capacity and vegetation coverage. In contrast, 1-allyl-3-vinylimidazolium chloride and N-allylimidazole may provide inferior crosslinking density and network stability than 1-allyl-1H-imidazole-2-amine when forming functional agents due to differences in their chemical structures, and therefore exhibit relatively low performance in practical applications.

[0088] The embodiments described above are only preferred embodiments of the present invention and are only used to explain the present invention, not to limit the scope of implementation of the present invention. For those skilled in the art, other implementation methods can certainly be easily made by replacement or modification based on the technical contents disclosed in this specification. Therefore, all changes and improvements made to the principles and process conditions of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A method for preparing environmentally friendly lightweight aggregate ecological concrete, characterized in that: Here’s how: Step 1: performing inorganic modification treatment on corn cob particles to obtain waterproof corn cob particles; Step 2: Add cement, fly ash, environmentally friendly sand, coarse ceramsite and fine ceramsite into a mixer and stir for 2 to 3 minutes to fully mix and obtain dry mixed powder; Step 3: Mix the dry mixed powder prepared in step 2, the functional agent and the waterproof corn cob particles prepared in step 1, add water and stir, put the mixture into a mold, and cure and shape it to obtain environmentally friendly lightweight aggregate ecological concrete; The inorganic modification treatment is: using a liquid waterproofing agent to waterproof the corn cob particles to obtain waterproof corn cob particles with a moist surface, and then placing the corn cob particles in an oven at a temperature of 100-110° C. for drying to obtain waterproof corn cob particles; The preparation method of the functional agent is as follows: S1, adding nonylphenol polyoxyethylene ether to dimethylformamide to obtain solution A, adding dimethyltriphenylmethane tetraisocyanate to dimethylformamide to obtain solution B, mixing solution A and solution B, and treating them in a high temperature environment to obtain a pretreated material; adding arabinoxylan to 1-allyl-1H-imidazole-2-amine, and stirring at high temperature and nitrogen protection conditions to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1 and treat at high temperature. After the mixture is cooled to room temperature, water is added for precipitation treatment, followed by filtration and freeze-drying to obtain a functional agent.

2. The method for preparing the environmentally friendly lightweight aggregate ecological concrete according to claim 1, characterized in that: The environmentally friendly lightweight aggregate ecological concrete is prepared from the following raw materials in parts by weight: 100-250 parts of cement, 100-250 parts of fly ash, 700-800 parts of environmentally friendly sand, 100-150 parts of fine ceramsite, 20-50 parts of coarse ceramsite, 1-3 parts of liquid waterproofing agent, 8-12 parts of functional agent, 5-30 parts of corn cob particles, and 250-280 parts of water.

3. The method for preparing the environmentally friendly lightweight aggregate ecological concrete according to claim 1 or 2, characterized in that: The liquid waterproofing agent is an organosilicon waterproofing agent.

4. The method for preparing the environmentally friendly lightweight aggregate ecological concrete according to claim 1 or 2, characterized in that: The average particle size of the fine ceramsite is 4-8 mm.

5. The method for preparing the environmentally friendly lightweight aggregate ecological concrete according to claim 1 or 2, characterized in that: The cement is at least one of sulphoaluminate cement and ordinary Portland cement.

6. The method for preparing the environmentally friendly lightweight aggregate ecological concrete according to claim 1 or 2, characterized in that: The average particle size of the coarse ceramsite is 10-15 mm.

7. The method for preparing the environmentally friendly lightweight aggregate ecological concrete according to claim 1, characterized in that: The curing and molding is carried out under the conditions of 92-98% relative humidity and 18-22° C.

8. The method for preparing the environmentally friendly lightweight aggregate ecological concrete according to claim 1 or 2, characterized in that: The preparation method of the functional agent is as follows, in parts by weight: S1, adding 1-3 parts of nonylphenol polyoxyethylene ether to 15-25 parts of dimethylformamide to obtain solution A, adding 8-12 parts of dimethyltriphenylmethane tetraisocyanate to 80-120 parts of dimethylformamide to obtain solution B, mixing solution A and solution B, and treating in an environment of 50-70° C. for 5-20 hours to obtain a pretreated product; 3-5 parts of arabinoxylan are added to 30-50 parts of 1-allyl-1H-imidazole-2-amine, and stirred at 30-45° C. under nitrogen protection for 1-5 hours to form a matrix solution; S2. Add the pretreated material prepared in step S1 to the matrix solution prepared in step S1, and treat at 60-80°C for 10-20 hours. After the mixture is cooled to room temperature, add 150-250 parts of water for precipitation treatment 1-3 times, and then filter and freeze-dry to obtain a functional agent.

9. An environmentally friendly lightweight aggregate ecological concrete, characterized in that: The method is prepared according to any one of claims 1 to 8.

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