Ecological concrete based on modified livistona chinensis fiber and lycoris powder film-coated fertilizer as well as preparation method and application of ecological concrete

Abstract

The invention discloses ecological concrete based on modified livistona chinensis fiber and lycoris powder film-coated fertilizer as well as a preparation method and application of the ecological concrete. The ecological concrete is prepared from the following raw materials in parts by weight: 200 to 400 parts of cement, 600 to 800 parts of coarse aggregate, 5 to 10 parts of modified livistona chinensis fiber, 20 to 60 parts of coated fertilizer particles, 50 to 140 parts of water and 1 to 3 parts of polycarboxylate superplasticizer. The livistona chinensis fiber has catalytic activity after being modified. And the film coating material of the film coating fertilizer particles is lycoris powder. By utilizing the synergistic effect of the modified livistona chinensis fiber and the lycoris powder, on one hand, the catalytic activity of the livistona chinensis is excited through particle treatment, the decomposition of the lycoris powder serving as a fertilizer coating material is facilitated, and the release rate of a fertilizer in concrete is increased; the bonding force between the livistona chinensis fibers and the concrete is enhanced, and the strength of the concrete is improved. On the basis that traditional plant fibers are utilized in concrete to improve the mechanical property of the concrete, the modified livistona chinensis fibers and the lycoris powder are innovatively and organically combined, so that the mechanical property of the ecological concrete is improved, and the fertilizer release rate is increased.

Description

Technical Field

[0001] The invention belongs to the field of ecological concrete, and in particular relates to ecological concrete based on modified palmetto fiber and Lycoris radiata powder coated fertilizer and a preparation method thereof. Background Art

[0002] Eco-concrete is an environmentally friendly building material with water permeability, vegetation and load-bearing functions, and is widely used in slope protection, river restoration and sponge city construction. Its core design concept is to form a connected pore structure through the accumulation of coarse aggregate to provide space for plant root growth and water penetration.

[0003] The application of traditional plant fibers in concrete has made certain progress. Through physical toughening, it can improve the crack resistance and durability of concrete. However, the single function of plant fibers in the existing technology limits its application potential, especially in terms of balancing the improvement of mechanical properties and functional synergy. Conventional fibers have weak interfacial bonding with the concrete matrix and lack adaptability to functional components, resulting in weak functional properties or limited improvement in mechanical properties. It is urgent to develop a new composite system that combines interface strengthening and functional properties.

[0004] Existing studies have not systematically explored the strengthening effect of fibers on the fiber-matrix bonding performance in concrete systems. Summary of the invention

[0005] The purpose of the present invention is to provide an ecological concrete based on modified palm fiber and Lycoris powder coated fertilizer and a preparation method thereof. The mechanical properties and fertilizer release rate of the ecological concrete are improved through the synergistic effect of the modified palm fiber and Lycoris powder.

[0006] To achieve the above-mentioned purpose, the present invention provides an ecological concrete based on modified palm fiber and Lycoris radiata powder coated fertilizer, the raw material composition and weight parts are: 200-400 parts of cement, 600-800 parts of coarse aggregate, 5-10 parts of modified palm fiber, 20-60 parts of coated fertilizer particles, 50-140 parts of water, and 1-3 parts of polycarboxylic acid water reducer; the coating material of the coated fertilizer particles is Lycoris radiata powder.

[0007] Furthermore, the modifier used to modify the palmetto fiber is nano-Al2O3, and the pretreated palmetto fiber is mixed with a nano-Al2O3 dispersion at a mass ratio of 1:3-1:5, and the nano-Al2O3 dispersion is prepared by dispersing nano-Al2O3 in deionized water at a concentration of 1-5wt%.

[0008] Furthermore, the pretreatment steps of the palmetto fiber include: washing to remove water-soluble organic matter, degumming, and drying.

[0009] Further, the preparation steps of the lycoris radiata powder and the fertilizer film coating steps include: crushing the lycoris radiata, removing the fibers in the crushed material to obtain a lycoris radiata powder milk, then washing, precipitating and drying the lycoris radiata powder milk to obtain the lycoris radiata powder; mixing the fertilizer particles with the lycoris radiata powder, and forming coated fertilizer particles by fluidized bed film coating.

[0010] Further, the adding sequence of the raw materials in the ecological concrete is as follows: dry-mix and stir cement, coarse aggregate and coated fertilizer particles; then add water and polycarboxylate water reducer and stir; then add modified Chinese fan palm fiber and stir; and then pour and mold.

[0011] Further, the specific steps of the pretreatment of the Chinese fan palm fiber are as follows:

[0012] (1) Cut the Chinese fan palm fiber into Chinese fan palm fiber segments;

[0013] (2) Use an ultrasonic cleaner to circulate and rinse the Chinese fan palm short fiber segments obtained in step (1) with pure water to remove surface sediment and water-soluble organic substances;

[0014] (3) Immerse and degum the Chinese fan palm short fiber obtained in step (2) with a mixed dye solution of NaOH, H2O2, sodium silicate and penetrant JFC at a temperature of 80-95 °C;

[0015] (4) Dry the Chinese fan palm fiber segments obtained in step (3) in three stages: the first stage: hot air drying to remove surface free water; the second stage: constant temperature drying to evaporate the water adsorbed on the cell wall; the third stage: vacuum drying to ensure that the moisture content ≤ 3%.

[0016] Further, the modification method of the Chinese fan palm fiber is specifically as follows: Select nano-Al2O3 as the Chinese fan palm fiber modifier; disperse nano-Al2O3 in deionized water at a concentration of 1-5 wt%, add polyethylene glycol as a dispersant, and use ultrasonic treatment to form a uniform suspension; mix the pretreated Chinese fan palm fiber with the nano-Al2O3 dispersion liquid at a mass ratio of 1:3-1:5, place it in a constant temperature magnetic stirrer and react for 1-2 hours at a temperature of 30-50 °C; filter out the Chinese fan palm fiber and dry it to obtain the modified Chinese fan palm fiber.

[0017] Further, the cement is sulfoaluminate cement; the particle size of the coarse aggregate is 5-20 mm.

[0018] Further, the fertilizer particles of the coated fertilizer particles are selected from one or a combination of more than two of ammonium persulfate fertilizer particles, ammonium nitrate fertilizer particles, potassium chloride, and calcium phosphate fertilizer particles.

[0019] This application also provides the application of the above ecological concrete in building materials.

[0020] In addition, the present application also provides a method for preparing the above-mentioned ecological concrete, which includes the following steps: preparing modified Chinese fan palm fibers and Lycoris radiata powder-coated fertilizer particles; dry-mixing and stirring cement, coarse aggregate, and powder-coated fertilizer particles; adding water and a polycarboxylate water reducer and stirring; then adding modified Chinese fan palm fibers and stirring; and pouring and molding.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The modified Chinese fan palm fibers of the present invention. As a natural cellulose material, after toughening treatment, the Chinese fan palm fibers can be used to improve the mechanical properties of concrete. At the same time, as a functional natural raw material rich in polysaccharide substances, the decomposition products of Lycoris radiata powder have excellent adhesiveness and gelling properties, making up for the interfacial defects between plant fibers and the cement matrix.

[0023] 2. The combined use of Lycoris radiata powder and modified Chinese fan palm fibers in the present invention has a good synergistic effect. On the one hand, the catalytic activity of the Chinese fan palm is stimulated through modification treatment, which is beneficial to the decomposition of the Lycoris radiata powder used as the fertilizer film material, improving the release rate of the fertilizer in the concrete. On the other hand, the decomposition products of Lycoris radiata powder have good adhesiveness and gelling properties, enhancing the bonding force between the Chinese fan palm fibers and the concrete and improving the strength of the concrete. Based on the use of traditional plant fibers in concrete to improve the mechanical properties of concrete, the present invention innovatively combines the modified Chinese fan palm fibers with Lycoris radiata powder organically, achieving the improvement of the mechanical properties of ecological concrete and the increase of the fertilizer release rate. Description of the Drawings

[0024] Figure 1 The flow diagram of a method for preparing ecological concrete based on modified Chinese fan palm fibers and Lycoris radiata powder-coated fertilizer provided by the present invention is given. Detailed Embodiments

[0025] To clearly illustrate the technical principle, beneficial effects, and implementation methods of the present invention, the technical solutions of the present invention will be further described in detail below with reference to specific embodiments. It should be emphasized that the following embodiments are only used to assist in understanding the technical features and implementation paths of the present invention, and do not limit the protection scope of the present invention. In addition, the technical elements involved in each embodiment can be combined or adjusted according to actual application requirements on the premise of not generating technical contradictions.

[0026] The present invention provides an ecological concrete based on modified Chinese fan palm fibers and Lycoris radiata powder-coated fertilizer. The raw materials include, by weight: 200 - 400 parts of cement, 600 - 800 parts of coarse aggregate, 5 - 10 parts of modified Chinese fan palm fibers, 20 - 60 parts of powder-coated fertilizer particles, 50 - 140 parts of water, and 1 - 3 parts of polycarboxylate water reducer.

[0027] Furthermore, the modified Chinese fan palm fiber is modified Chinese fan palm fiber, and the Chinese fan palm fiber needs to be pretreated. The specific steps of the pretreatment are as follows:

[0028] (1) Cut the Chinese fan palm fiber into Chinese fan palm fiber segments with a length of 20 - 30 mm, and the incision angle is 45°.

[0029] (2) Use a 40 kHz ultrasonic cleaner to circulate and rinse the Chinese fan palm short fiber segments obtained in step (1) with pure water at 50 °C for 20 minutes to remove surface sediment and soluble organic matter.

[0030] (3) Immerse and degum the Chinese fan palm short fiber obtained in step (2) with a mixed dye solution with a mass concentration of 6 g / L of NaOH, 8 g / L of H₂O₂, 3 g / L of sodium silicate, and 2 g / L of penetrant JFC under the conditions of a bath ratio of 1∶10 and a temperature of 85 °C for 90 min.

[0031] (4) Dry the Chinese fan palm fiber segments obtained in step (3) in three stages: The first stage: hot air dry at 40 °C for 1 hour to remove surface free water; The second stage: constant temperature dry at 60 °C for 1 hour to evaporate the water adsorbed on the cell wall; The third stage: vacuum dry at 80 °C for 1 hour (vacuum degree -0.08 MPa) to ensure that the moisture content ≤ 3%.

[0032] After being pretreated by cutting, ultrasonic cleaning, alkali-oxygen composite degumming, and multi-stage gradient drying, the Chinese fan palm fiber forms a regular interfacial orientation and a loose surface structure, improving the fiber toughness. At the same time, the graded drying enhances the fiber adsorption, providing an optimized carrier substrate for subsequent particle loading.

[0033] Furthermore, the preparation method of the modified Chinese fan palm fiber includes: obtaining the modified Chinese fan palm fiber from the pretreated Chinese fan palm fiber segments through the particle treatment method.

[0034] Furthermore, the nanoparticle treatment method includes: Select nano-Al₂O₃ as the Chinese fan palm fiber modifier. Disperse nano-Al₂O₃ in deionized water at a concentration of 1 - 5 wt%, add 0.1% polyethylene glycol as a dispersant, and perform ultrasonic treatment at 40 kHz for 20 minutes to form a uniform suspension. Mix the pretreated Chinese fan palm fiber with the nano-Al₂O₃ dispersion liquid at a mass ratio of 1:3 - 1:5, place it in a constant temperature magnetic stirrer (rotation speed 500 - 800 rpm, temperature 40 °C) and react for 1 - 2 hours, filter out the Chinese fan palm fiber, and dry it to obtain the modified Chinese fan palm fiber.

[0035] The modified Chinese fan palm fiber plays the role of a decomposition reaction catalyst, which is beneficial to the decomposition of the lycoris radiata powder used as the fertilizer film material and improves the fertilizer release rate in the concrete.

[0036] Further, the fertilizer granules of the film-coated fertilizer granules are selected from one or more combinations of ammonium persulfate fertilizer granules, ammonium nitrate fertilizer granules, potassium chloride, and calcium phosphate fertilizer granules, preferably potassium chloride fertilizer granules; the film-coated material is lycoris powder.

[0037] Further, the specific steps for preparing the lycoris powder are as follows:

[0038] (1) Thoroughly rinse the surface of the lycoris bulbs with clean water to remove attached impurities;

[0039] (2) Cut the lycoris bulbs obtained in step (1) into small sections with a knife and crush them into a pulp with a pulverizer. The pulp and lycoris bulb fibers after the first crushing are put into the pulverizer again for crushing to improve the powder yield;

[0040] (3) Put the mixture of the pulp and lycoris bulb fibers obtained in step (2) into a gauze, tighten the gauze for filtration, and separate the lycoris bulb fibers and lycoris powder milk. Then put the lycoris powder milk into a pool filled with clean water and stir it several times with a stirrer.

[0041] (4) Sieve the separated lycoris powder milk obtained in step (3) to sieve out the fine fibers after the separation of the lycoris powder.

[0042] (5) Put the lycoris powder milk obtained in step (4) into a pool and let it settle naturally for 24 hours.

[0043] (6) Pour out the upper waste slurry in the pool in step (5) to separate the lycoris powder.

[0044] (7) Add clean water to the lycoris powder obtained in step (6) again to form a suspended lycoris powder milk.

[0045] (8) Put the suspended lycoris powder milk obtained in step (7) into water and let it settle naturally again to obtain a lycoris powder precipitate.

[0046] (9) Predry the lycoris powder precipitate obtained in step (8) with a dryer. When the moisture content is not much, then dry it naturally to obtain the lycoris powder.

[0047] The lycoris powder prepared by cleaning, crushing, fiber separation, multi-stage precipitation and drying treatment has a particle size range of 50 - 200 microns and a specific surface area > 2.5 m 2 / g. Its particles are uniform and the surface structure is dense. It has both decomposability and adhesion stability, and can effectively form a continuous film-coated layer, which is suitable for preparing a film-coated material for fertilizers.

[0048] Further, the specific steps for preparing the film-coated fertilizer granules are as follows: Mix the potassium chloride fertilizer granules with the precipitate, and form film-coated fertilizer granules by fluidized bed film coating.

[0049] Further, the cement is sulfoaluminate cement; the coarse aggregate is crushed stone with a particle size of 5-20 mm.

[0050] A preparation method of ecological concrete based on modified Chinese fan palm fiber and lycoris radiata powder-coated fertilizer, comprising the following steps:

[0051] Dry-mix the cement, coarse aggregate, and coated fertilizer particles, and stir slowly for 2-3 minutes; add water and polycarboxylate water reducer, and stir slowly for 1-2 minutes; then stir quickly for 2-3 minutes; then uniformly add the modified Chinese fan palm fiber within 1 minute of quick stirring; finally, stir quickly for 3-4 minutes; pour and mold.

[0052] Further, after pouring and molding, it is cured under the conditions of 95% relative humidity and 20±2°C.

[0053] Example 1

[0054] An ecological concrete based on modified Chinese fan palm fiber and lycoris radiata powder-coated fertilizer, by mass, includes:

[0055] 300 parts of sulfoaluminate cement, 700 parts of crushed stone, 6 parts of modified Chinese fan palm fiber, 20 parts of coated fertilizer particles, 90 parts of water, and 2 parts of polycarboxylate water reducer.

[0056] Among them, the preparation method of the modified Chinese fan palm fiber is as follows:

[0057] Cut the Chinese fan palm fiber into Chinese fan palm fiber segments with a length of 20-30 mm, and then use a 40 kHz ultrasonic cleaner to rinse with pure water at 50°C for 20 minutes in a circulating manner. After rinsing, use a mixed dye solution with a NaOH mass concentration of 6 g / L, an H2O2 mass concentration of 8 g / L, a sodium silicate mass concentration of 3 g / L, and a penetrant JFC mass concentration of 2 g / L, and carry out degumming treatment by dipping at a bath ratio of 1:10 and a temperature of 85°C for 90 min. The obtained Chinese fan palm fiber segments after degumming treatment are dried in three stages: the first stage: hot air drying at 40°C for 1 hour to remove surface free water; the second stage: constant temperature drying at 60°C for 1 hour to evaporate the water adsorbed on the cell wall; the third stage: vacuum drying at 80°C for 1 hour (vacuum degree -0.08 MPa). Select nano-Al2O3 as the Chinese fan palm fiber modifier, disperse nano-Al2O3 in deionized water at a concentration of 1-5 wt%, add 0.1% polyethylene glycol as a dispersant, and carry out ultrasonic treatment at 40 kHz for 20 minutes to form a uniform suspension. Mix the dried Chinese fan palm fiber with the nano-Al2O3 dispersion liquid at a mass ratio of 1:3-1:5, place it in a constant temperature magnetic stirrer (rotation speed 500-800 rpm, temperature 40°C) and react for 1-2 hours, filter out the Chinese fan palm fiber, and dry it to obtain the modified Chinese fan palm fiber.

[0058] Among them, the preparation method of the coated fertilizer particles is as follows:

[0059] Thoroughly rinse the surface of Lycoris radiata bulbs with clean water. Cut the Lycoris radiata bulbs into small sections with a knife and crush them into a pulp with a pulverizer. Put the pulp after the first crushing and the Lycoris radiata bulb fibers into the pulverizer for secondary crushing. Load the mixture of the pulp and the Lycoris radiata bulb fibers and the mixture of the Lycoris radiata bulb fibers into a gauze, tighten the gauze for filtration, and separate the Lycoris radiata bulb fibers and the Lycoris radiata powder milk. Then put the Lycoris radiata powder milk into a pool filled with clean water and stir it multiple times with a stirrer. Sieve the Lycoris radiata powder milk to sieve out the fine fibers separated from the Lycoris radiata powder. Put the Lycoris radiata powder milk into the pool and let it settle naturally for 24 hours. Pour out the upper waste slurry in the pool to separate the Lycoris radiata powder. Add clean water to the Lycoris radiata powder again to form a suspended Lycoris radiata powder milk. The suspended Lycoris radiata powder milk is put into water and allowed to settle naturally again to obtain the Lycoris radiata powder precipitate. The Lycoris radiata powder precipitate is pre-dried with a dryer, and when the moisture content is not much, it is then naturally dried to obtain the Lycoris radiata powder. Mix the potassium chloride fertilizer granules with the Lycoris radiata powder and form coated fertilizer granules by fluidized bed coating.

[0060] The preparation of ecological concrete based on modified Chinese fan palm fibers and Lycoris radiata powder coated fertilizer includes:

[0061] Dry-mix cement, coarse aggregate, and coated fertilizer granules, and stir slowly for 2 - 3 minutes; add water and polycarboxylate water reducer, and stir slowly for 1 - 2 minutes; then stir quickly for 2 - 3 minutes; then uniformly add modified Chinese fan palm fibers within 1 minute of quick stirring; finally stir quickly for 3 - 4 minutes; pour and mold. Cure under the conditions of 95% relative humidity and 20 ± 2°C.

[0062] Example 2

[0063] The difference from Example 1 is that the modified Chinese fan palm fibers are replaced with unmodified Chinese fan palm fibers.

[0064] Example 3

[0065] The difference from Example 1 is that the number of parts of modified Chinese fan palm fibers added is 7.

[0066] Comparative Example 1

[0067] The difference from Example 1 is that the coating material of the coated fertilizer granules is resin.

[0068] Comparative Example 2

[0069] The differences from Example 1 are that the modified Chinese fan palm fibers are replaced with unmodified Chinese fan palm fibers. The coating material of the coated fertilizer granules is resin.

[0070] Comparative Example 3

[0071] The difference from Example 1 is that no modified Chinese fan palm fibers and coated fertilizer granules are added.

[0072] Refer to the "Standard Test Methods for Physical and Mechanical Properties of Concrete (GBT50081-2019)" to test the strength of ecological concrete.

[0073] First, measure the external volume V of the concrete specimen. Then, determine the mass of the concrete specimen and keep it in a drying oven at 100 - 110 °C for at least 24 hours. After taking out the specimen, let the specimen cool in a dry environment to 20 - 25 °C, and then weigh its mass with an electronic balance. Record the mass as M2. Immerse the finally cooled and dried concrete specimen in water at about 21 °C for at least 48 hours until the mass increase value of two consecutive surface-dried specimens within a 24-hour interval is less than 0.5% of the measured maximum value. Then, weigh its mass with an electronic balance and record the mass as M1. Then, the porosity = (1 - (M1 - M2) / (ρ_water × V)) × 100%.

[0074] Taking potassium ions as an example, test the release effect of potassium ions in the ecological concrete specimen: Put a porous ecological concrete specimen with a volume of 100×100×100 mm into a container of 200×200×200 mm 3 Add 5 L of water, seal it with fresh-keeping film, and place it in a curing room at 20 °C; Take samples on the 1st, 7th, 14th, 28th, and 56th days respectively, and test the potassium ion content according to GB / T7476-1987.

[0075] Table 1 Raw material ratios and performance characterizations of examples and comparative examples

[0076]

[0077] As can be seen from Table 1, by comparing Example 1 with Example 2, it is found that the modified Chinese fan palm fiber has catalytic activity, which promotes the decomposition of the fertilizer film material, lycoris radiata powder, so that the release rate of the fertilizer in the concrete is increased by 24.3%. At the same time, the substances generated after the decomposition of lycoris radiata powder enhance the adhesion between the Chinese fan palm fiber and the concrete, and the 28-day compressive strength of the concrete is increased by 10.5%. By comparing Example 1 with Comparative Example 1 and Example 2 with Comparative Example 2 respectively, it is found that whether the Chinese fan palm fiber is modified or not, the Chinese fan palm fiber and the conventional resin film material do not produce a synergistic effect in the concrete, and there is no improvement effect on the mechanical properties and fertilizer release rate of the concrete. By comparing Comparative Example 3 with other examples, it is found that the addition of fibers has an effect on improving the mechanical properties and increasing the porosity of the concrete. The reason is that the fibers can control the further development of the cracks in the matrix concrete, so that the strength of the concrete is improved. Further comparing Example 1 with Example 3, it is found that the increase in the amount of modified Chinese fan palm fiber has a certain effect on improving the mechanical properties of the concrete and increasing the fertilizer release rate. The amount of modified Chinese fan palm fiber is increased by 16.7%, the 28-day compressive strength of the concrete is increased by 5.4%, and the fertilizer release rate is increased by 8.0%. The reason for the analysis is that the increase in the strength of the concrete is because the modified Chinese fan palm fiber inhibits the cracks in the matrix concrete. At the same time, the modified Chinese fan palm fiber will form pores in the matrix of the concrete that are beneficial to the adhesion of the film-coated fertilizer particles, and it can also be used as an effective carrier for the adhesion of the film-coated fertilizer particles. Therefore, under the condition that the total amount of fertilizer remains unchanged, due to the dual physical effects of the modified Chinese fan palm fiber on the effective adhesion of the film-coated fertilizer particles, the fertilizer release rate of the concrete is further increased.

[0078] Those skilled in the art should understand that the above embodiments are only preferred descriptions of the present invention and should not be construed as limitations of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall be covered by the scope of the claims of the present invention.

Claims

1. An ecological concrete based on modified palm fiber and Lycoris radiata powder coated fertilizer, characterized in that: The raw material composition and weight parts are: 200-400 parts of cement, 600-800 parts of coarse aggregate, 5-10 parts of modified palm fiber, 20-60 parts of film-coated fertilizer particles, 50-140 parts of water, and 1-3 parts of polycarboxylic acid water reducer; the film-coated material of the film-coated fertilizer particles is Lycoris radiata powder.

2. The ecological concrete according to claim 1, characterized in that: The modifier used for modifying the palmetto fiber is nano-Al2O3. The pretreated palmetto fiber is mixed with the nano-Al2O3 dispersion at a mass ratio of 1:3-1:

5. The nano-Al2O3 dispersion is prepared by dispersing the nano-Al2O3 in deionized water at a concentration of 1-5wt%.

3. The ecological concrete according to claim 2, characterized in that: The pretreatment steps of the palmetto fiber include: washing to remove water-soluble organic matter, degumming, and drying.

4. The ecological concrete according to claim 1, characterized in that: The preparation steps of lycoris powder and fertilizer coating steps include: crushing lycoris, removing fibers from the crushed material to obtain lycoris powder milk, then washing the lycoris powder milk, precipitating and drying it to obtain lycoris powder; mixing fertilizer granules with lycoris powder, and coating with a fluidized bed to form coated fertilizer granules.

5. The ecological concrete according to claim 1, characterized in that: The order of adding raw materials into the ecological concrete is: dry-mixing cement, coarse aggregate and coated fertilizer particles and stirring; then adding water and polycarboxylic acid water reducer and stirring; then adding modified palm fiber and stirring; and pouring and forming.

6. The ecological concrete according to claim 3, characterized in that: The specific steps of pretreatment of palmetto fiber are as follows: (1) cutting the palmetto fiber into palmetto fiber segments; (2) The palmetto staple fiber segments obtained in step (1) are rinsed with pure water in an ultrasonic cleaning machine to remove surface sediment and water-soluble organic matter; (3) treating the palmetto staple fibers obtained in step (2) with a mixed dye solution of NaOH, H2O2, sodium silicate, and penetrant JFC at a temperature of 80-95 degrees Celsius for degumming; (4) Drying the palmetto fiber segments obtained in step (3) in three stages: the first stage: hot air drying to remove free water on the surface; the second stage: constant temperature drying to evaporate water adsorbed on the cell wall; and the third stage: vacuum drying to ensure that the moisture content is ≤3%.

7. The ecological concrete according to claim 2, characterized in that: The modification method of the palmetto fiber is as follows: using nano-Al2O3 as a palmetto fiber modifier; dispersing the nano-Al2O3 in deionized water at a concentration of 1-5wt%, adding polyethylene glycol as a dispersant, and using ultrasonic treatment to form a uniform suspension; The pretreated palmetto fiber and nano-Al2O3 dispersion are mixed in a mass ratio of 1:3-1:5, placed in a constant temperature magnetic stirrer for reaction for 1-2 hours at a temperature of 30-50°C; the palmetto fiber is filtered out and dried to obtain modified palmetto fiber.

8. The ecological concrete according to claim 1, characterized in that: The cement is sulphoaluminate cement; the particle size of the coarse aggregate is 5-20 mm.

9. Use of the ecological concrete according to any one of claims 1 to 8 in building materials.

10. A method for preparing ecological concrete as described in any one of claims 1 to 8, characterized in that it comprises the following steps: preparing modified palm fiber and Lycoris radiata powder coated fertilizer granules; dry mixing cement, coarse aggregate and coated fertilizer granules and stirring; then adding water and polycarboxylic acid water reducer and stirring; then adding modified palm fiber and stirring; and casting and forming.

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