Vegetation type porous ecological concrete as well as preparation method and application thereof

Abstract

The invention discloses vegetation type porous ecological concrete as well as a preparation method and application thereof. The concrete is prepared from the following components in parts by mass: 1200-1500 parts of modified oyster shells, 250-350 parts of a composite cementing material, 100-130 parts of water, 2-3 parts of a water reducing agent, 15-25 parts of plant fibers, 3-5 parts of a water retaining agent and 5-10 parts of butyl stearate. The modified oyster shells are subjected to acid and alkali treatment, and the composite cementing material is prepared from ordinary Portland cement, metakaolin and silica fume according to a specific proportion. The preparation method comprises the steps of premixing, stirring, adding of the modified oyster shells, pouring forming, curing and the like. The concrete is high in porosity, good in air permeability and excellent in water-retaining property, the compressive strength of the concrete meets the use requirements, the concrete is suitable for being used as a plant culture medium for landscape architecture, slope protection greening, roof greening and the like, a good environment can be provided for plant growth, and the concrete is also beneficial to plant growth in extreme climate.

Description

Technical Field

[0001] The present invention belongs to the technical field of vegetative porous ecological concrete, and more specifically, the present invention relates to a vegetative porous ecological concrete and a preparation method and application thereof. Background Art

[0002] As urban construction continues to advance, greening of roads and garden landscapes has become a key link in improving the quality of urban ecological environment. As a new type of greening material, vegetative porous concrete has shown application potential in the field of plant culture media due to its unique pore structure and certain mechanical properties, and has attracted much attention from scientific researchers and engineers. However, from the perspective of actual application effects and existing research results, the existing technology of vegetative porous concrete still has many defects to be solved when it is used to plant flowers on roads, garden landscapes, etc.

[0003] As pointed out in the authorized text of the prior art announcement number CN115611587B, "A Vegetative Porous Concrete, Its Preparation Method and Application", a large amount of discarded oyster shells are generated every year, and traditional treatment methods cause environmental pollution and waste of resources. At the same time, with the popularization of urban concrete structure construction, urban greening has put forward new requirements for concrete structures. Ordinary sandstone concrete has low porosity and high alkalinity, which is difficult to meet the needs of plant growth; and although the commonly used porous concrete has a pore structure that is conducive to plant rooting, the porosity is negatively correlated with the compressive strength. When ensuring the adaptability of plants, the durability of the project will be reduced. This situation highlights the urgency of developing new types of vegetative porous concrete.

[0004] In terms of temperature regulation and extreme climate adaptation, the shortcomings of existing vegetative porous concrete are also quite obvious. Roads and landscapes are directly exposed to the natural environment for a long time, and the temperature changes dramatically, especially the high temperature in summer, which poses a serious threat to the growth of flowers. The current vegetative porous concrete lacks an effective temperature regulation mechanism and cannot cool the roots of flowers at high temperatures. In the hot summer, excessively high temperatures will inhibit the normal physiological activities of the roots of flowers, resulting in slow root growth, decreased absorption capacity, and even root damage, which greatly limits the growth and survival of flowers in different seasons.

[0005] In addition, it is difficult to achieve an effective balance between the temperature regulation, porosity, compressive strength, air permeability and water retention of vegetative porous concrete. These properties affect each other, and changing one of them may often lead to the deterioration of other properties. For example, reducing the amount of cementitious materials to increase porosity will reduce compressive strength; increasing the amount of water retaining agent may affect the air permeability and stability of the pore structure. This contradiction between properties has an adverse effect on the growth of flowers. Solving these problems is of great practical significance for improving the effect of urban greening, ensuring the healthy growth of flowers, and improving the quality of urban ecological environment. Summary of the Invention

[0006] An object of the present invention is to solve at least the above-mentioned defects and provide at least the advantages described hereinafter.

[0007] The present invention provides a vegetative porous ecological concrete, its preparation method and application, aiming to develop a vegetative porous ecological concrete with better performance and more capable of meeting the urban greening needs.

[0008] A vegetative porous ecological concrete provided by the present invention is made of the following raw materials by mass fraction: Modified oyster shell: 1200 - 1500 parts; Composite cementitious material: 250 - 350 parts; Water: 100 - 130 parts; Water reducing agent: 2 - 3 parts; Plant fiber: 15 - 25 parts; Water retaining agent: 3 - 5 parts; Butyl stearate: 5 - 10 parts.

[0009] Preferably, the preparation method of the modified oyster shell in the raw materials is as follows: wash the oyster shell and crush it into fragments with a particle size of 5 - 10 mm; put the oyster shell fragments into a hydrochloric acid solution with a concentration of 0.5 - 1 mol / L and soak for 2 - 3 hours, then rinse the acid-treated oyster shell fragments with clean water until neutral, and then put them into a sodium hydroxide solution with a concentration of 0.3 - 0.5 mol / L and soak for 1 - 2 hours. After the soaking is completed, rinse the oyster shell fragments with clean water again, and then dry them to constant weight in an oven at 100 - 120 °C.

[0010] Preferably, the composite cementitious material is composed of ordinary Portland cement, metakaolin, and silica fume mixed in a ratio of 6:3:1, wherein the strength grade of the ordinary Portland cement is 42.5.

[0011] Preferably, the water reducing agent is naphthalene sulfonate formaldehyde polymer.

[0012] Preferably, the plant fiber is one or more of rice husk fiber and coconut fiber, and is crushed to a length of 2.5 - 8 mm.

[0013] Preferably, the water retaining agent is sodium polyacrylate.

[0014] The present invention also provides a preparation method of a vegetative porous ecological concrete, which includes the following steps: Premix the plant fiber and the water retaining agent: mix the plant fiber and the water retaining agent evenly; Concrete mixing: Mix the composite cementitious material, water, and water reducer to form a uniform cement paste; then add the pre-mixed plant fiber and water retainer, and continue mixing to evenly distribute the plant fiber and water retainer in the paste; finally, add butyl stearate and mix to ensure that butyl stearate is fully dispersed and evenly mixed to obtain a concrete paste; Adding modified oyster shells: Add the modified oyster shells to the well-mixed concrete paste and mix to evenly coat the modified oyster shells in the paste to form a porous concrete paste; Pouring and molding: Pour the porous concrete paste into a mold, and then place the mold in a curing room for curing to obtain a vegetative porous ecological concrete product.

[0015] The present invention also provides the application of the vegetative porous ecological concrete, which is applied to garden landscapes, slope greening, and roof greening as a plant culture medium.

[0016] The present invention has at least the following beneficial effects: First, due to the porous nature of the modified oyster shells in the present invention, combined with rice husk fiber, the porosity and connectivity are greatly increased. The porosity reaches 29.1% - 38.6%, far exceeding the comparative example. It creates sufficient space for the extension of plant roots, facilitating the roots to absorb nutrients. Butyl stearate maintains the stability of the pores, prevents blockage, and ensures the root growth environment.

[0017] Second, through the synergistic effect of the composite cementitious material, modified oyster shells, butyl stearate, and rice husk fiber in the present invention, while meeting the porosity required for plant growth, the compressive strength reaches 5.5 - 9.3 MPa, higher than the comparative example. It ensures that the concrete can withstand a certain external force when used as a plant culture medium, maintains the stability of the plant growth environment, and is not easily deformed or damaged.

[0018] Third, the porous structure of the modified oyster shells in the present invention forms connected pores with the rice husk fiber, and butyl stearate reduces the surface energy of the pores, preventing water blockage, so that the air flow rate reaches 58 - 85 cm³ / min, significantly higher than the comparative example. It can provide sufficient oxygen for plant roots, meet the respiration, and promote the healthy growth of plants.

[0019] Fourth, through the synergy of the modified oyster shells, rice husk fiber, and sodium polyacrylate water retainer in the present invention, the water storage space is increased, and butyl stearate prevents water from evaporating too quickly. The water retention rate is 78% - 90% after 24 hours of drying and 69% - 81% after 48 hours, far higher than the comparative example. It can continuously and stably supply water to plants in a dry environment. Moreover, in the simulated extreme climate experiment, the growth of plants in the experimental group is less affected, reflecting the good promotion effect of the concrete of the present invention on plant growth and its adaptability in extreme climates.

[0020] Fifthly, by using waste oyster shells as raw materials, the present invention reduces environmental pollution and waste of resources, realizes the resource utilization of waste, and conforms to the concept of sustainable development.

[0021] Other advantages, objectives and features of the present invention will be partially reflected by the following description, and partially will be understood by those skilled in the art through the research and practice of the present invention. Detailed implementation manners

[0022] The following further elaborates on the present invention in conjunction with embodiments, so that those skilled in the art can implement it with reference to the text of the specification.

[0023] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation schemes are all conventional methods, and the reagents and materials, unless otherwise specified, can all be obtained from commercial channels; during the test implementation process, cube molds with side lengths of 100 mm or 200 mm or other required molds can be selected.

[0024] Example 1 A vegetative porous ecological concrete is made from the following raw materials by mass: Modified oyster shells: 1200 parts; Composite cementitious material: 350 parts; Water: 130 parts; Water reducer: 3 parts; Plant fiber: 25 parts; Water retaining agent: 5 parts; Butyl stearate: 10 parts.

[0025] Among them, the preparation method of the modified oyster shells is as follows: Wash the oyster shells and crush them into fragments with a particle size of 10 mm; put the oyster shell fragments into a hydrochloric acid solution with a concentration of 1 mol / L and soak for 3 hours, then rinse the acid-treated oyster shell fragments with clean water until neutral, and then put them into a sodium hydroxide solution with a concentration of 0.5 mol / L and soak for 2 hours. After the soaking is over, rinse the oyster shell fragments with clean water again, and then dry them to constant weight in an oven at 120 °C.

[0026] The composite cementitious material is weighed according to the ratio of 6:3:1 of ordinary Portland cement, metakaolin, and silica fume, and poured into a forced mixer and stirred for 10 minutes to make the three materials fully and evenly mixed; among them, the strength grade of the ordinary Portland cement is 42.5; The water reducer is naphthalene sulfonate formaldehyde polymer.

[0027] The plant fiber is coconut fiber and is crushed to a length of 8 mm.

[0028] The water retaining agent is sodium polyacrylate.

[0029] The vegetative porous ecological concrete product is prepared by the following method: Pour the composite cementitious material into a mixing container, slowly add water and water reducer, and stir for 5 - 6 minutes to make them evenly mixed to form a cementitious material slurry. Then, while stirring, slowly add the modified oyster shell and continue stirring for 5 - 6 minutes to make it preliminarily evenly mixed. Next, add plant fiber and stir for 3 - 4 minutes. Then add the water retaining agent and stir for 2 - 3 minutes. Finally, add butyl stearate and stir for 5 - 6 minutes until all materials are completely mixed to obtain the vegetative porous ecological concrete slurry. Then pour the prepared concrete slurry into a mold and perform vibration molding, controlling the vibration time within 5 - 6 minutes to discharge air bubbles. After molding, place the mold and the concrete in an environment with a temperature of about 20°C and high humidity for curing for 2 days, then remove the mold, and continue curing for 10 days, during which sprinkle water regularly to keep it moist.

[0030] Example 2 A vegetative porous ecological concrete is made from the following raw materials by mass fraction: Modified oyster shell: 1500 parts; Composite cementitious material: 250 parts; Water: 100 parts; Water reducer: 2 parts; Plant fiber: 15 parts; Water retaining agent: 3 parts; Butyl stearate: 5 parts.

[0031] Among them, the preparation method of the modified oyster shell is: wash the oyster shell and crush it into fragments with a particle size of 5 mm; put the oyster shell fragments into a hydrochloric acid solution with a concentration of 0.5 mol / L and soak for 2 hours, then rinse the acid-treated oyster shell fragments with clean water until neutral, and then put them into a sodium hydroxide solution with a concentration of 0.3 mol / L and soak for 1 hour. After the soaking is completed, rinse the oyster shell fragments with clean water again, and then dry them in an oven at 100°C until constant weight.

[0032] Weigh ordinary Portland cement, metakaolin, and silica fume in a ratio of 6:3:1 for the composite cementitious material, pour them into a forced mixer, and stir for 10 minutes to make the three materials fully and evenly mixed; among them, the strength grade of the ordinary Portland cement is 42.5; The water reducer is naphthalene sulfonate formaldehyde polymer.

[0033] The plant fiber is rice husk fiber and is crushed to a length of 2.5 mm.

[0034] The water retaining agent is sodium polyacrylate.

[0035] The vegetative porous ecological concrete product is prepared by the following method: Pour the composite cementitious material into a stirring container, slowly add water and water reducer, and stir for 5 - 6 minutes to make them mix evenly to form a cementitious material slurry. Then, while stirring, slowly add the modified oyster shell and continue stirring for 5 - 6 minutes to make a preliminary even mixture. Next, add the plant fiber and stir for 3 - 4 minutes. Then add the water retaining agent and stir for 2 - 3 minutes. Finally, add butyl stearate and stir for 5 - 6 minutes until all materials are completely mixed to obtain the vegetative porous ecological concrete slurry. Then pour the prepared concrete slurry into a mold and vibrate for molding. The vibration time is controlled within 5 - 6 minutes to discharge air bubbles. After molding, place the mold and the concrete in an environment with a temperature of about 20°C and high humidity for curing for 2 days, then remove the mold, and continue curing for 10 days, during which sprinkle water regularly to keep it moist.

[0036] Example 3 A vegetative porous ecological concrete is made from the following raw materials by mass fraction: Modified oyster shell: 1500 parts; Composite cementitious material: 250 parts; Water: 100 parts; Water reducer (naphthalene sulfonate formaldehyde polymer): 2 parts; Plant fiber (rice husk fiber, crushed to a length of 2.5 mm): 15 parts; Water retaining agent (sodium polyacrylate): 3 parts; Butyl stearate: 5 parts.

[0037] The vegetative porous ecological concrete product is prepared by the following method: Preparation of modified oyster shell: Wash the oyster shell and crush it into fragments with a particle size of 5 mm; put the oyster shell fragments into a hydrochloric acid solution with a concentration of 0.5 mol / L and soak for 2 hours. Then rinse the acid-treated oyster shell fragments with clean water until neutral, and then put them into a sodium hydroxide solution with a concentration of 0.3 mol / L and soak for 1 hour. After soaking, rinse the oyster shell fragments with clean water again, and then dry them in an oven at 100°C until constant weight. Mixing of composite cementitious material: Weigh ordinary Portland cement, metakaolin, and silica fume in a ratio of 6:3:1, pour them into a forced mixer, and stir for 10 minutes to make the three materials fully and evenly mixed; among them, the strength grade of the ordinary Portland cement is 42.5. Premix plant fiber and water retaining agent: Put the crushed plant fiber and water retaining agent into a small mixer and stir at low speed for 5 - 8 minutes to make a preliminary even mixture of the two. Concrete mixing: Add the mixed composite cementitious materials into a large mixer, then add water and water reducer, and stir at low speed for 3 - 5 minutes to form a uniform cement paste; then add the pre-mixed plant fibers and water retainers, and continue to stir for 5 - 8 minutes to evenly distribute the plant fibers and water retainers in the paste; finally, add butyl stearate and stir for 3 - 5 minutes to ensure that butyl stearate is fully dispersed and evenly mixed with other materials to obtain a concrete paste; Adding modified oyster shells: Slowly add the prepared modified oyster shells into the stirred concrete paste and stir for 8 - 10 minutes to evenly coat the modified oyster shells in the paste, forming a porous concrete paste with certain fluidity and plasticity; Pouring and molding: Pour the porous concrete paste into a pre-prepared mold, and adopt the method of layered pouring, with the thickness of each layer controlled at 4 - 6 cm, and vibrate for 1 - 2 minutes with a vibrator after each layer is poured; Curing: After pouring is completed, place the mold in a curing room with a temperature of 20 ± 2°C and a relative humidity greater than 90% for curing. In the initial stage of curing (2 days), after taking out and removing the mold, the humidity can be appropriately reduced, but the surface of the concrete still needs to be kept moist. The total curing time is 10 days to obtain a vegetative porous ecological concrete product.

[0038] Comparative Example 1 A vegetative porous ecological concrete, which is different from Example 3 in that it does not contain butyl stearate, rice husk fiber and sodium polyacrylate. Specifically, in terms of mass parts, it is made from the following raw materials: Modified oyster shells: 1500 parts; Composite cementitious materials: 250 parts; Water: 100 parts; Water reducer (naphthalene sulfonate formaldehyde polymer): 2 parts.

[0039] The vegetative porous ecological concrete product is prepared by the following method: Preparation of modified oyster shells: Wash the oyster shells and crush them into fragments with a particle size of 5 mm; put the oyster shell fragments into a hydrochloric acid solution with a concentration of 0.5 mol / L and soak for 2 hours, then rinse the acid-treated oyster shell fragments with clean water until neutral, and then put them into a sodium hydroxide solution with a concentration of 0.3 mol / L and soak for 1 hour. After soaking, rinse the oyster shell fragments with clean water again, and then dry them in an oven at 100°C to constant weight; Mixing of composite cementitious materials: Weigh ordinary Portland cement, metakaolin, and silica fume in a ratio of 6:3:1, pour them into a forced mixer, and stir for 10 - 15 minutes to fully and evenly mix the three materials; Concrete mixing: Add the mixed composite cementitious material into a large mixer, then add water and water reducer, and stir at low speed for 3 - 5 minutes to form a uniform cement paste; then add the water retention agent and continue to stir for 5 - 8 minutes to evenly distribute the water retention agent in the paste and obtain a concrete paste through uniform mixing. Adding modified oyster shells: Slowly add the prepared modified oyster shells into the well - stirred concrete paste and stir for 8 - 10 minutes to evenly wrap the modified oyster shells in the paste, forming a porous concrete paste with a certain fluidity and plasticity. Pouring and molding: Pour the porous concrete paste into a pre - prepared mold, and use the method of layered pouring. The thickness of each layer is controlled at 4 - 6 cm, and after each layer is poured, vibrate with a vibrating rod for 1 - 2 minutes. Curing: After pouring is completed, place the mold in a curing room with a temperature of 20 ± 2°C and a relative humidity greater than 90%. In the initial stage of curing (2 days), after removing the mold, the humidity can be appropriately reduced, but the concrete surface still needs to be kept moist. The total curing time is 10 days to obtain the vegetation - type porous ecological concrete products.

[0040] Comparative Example 2 A vegetation - type porous ecological concrete, which is different from Example 3 in that it does not contain butyl stearate and rice husk fiber. Specifically, in terms of mass parts, it is made from the following raw materials: Modified oyster shells: 1500 parts; Composite cementitious material: 250 parts; Water: 100 parts; Water reducer (naphthalene sulfonate formaldehyde polymer): 2 parts; Water retention agent (sodium polyacrylate): 3 parts.

[0041] The vegetation - type porous ecological concrete products are prepared through the following method: Preparation of modified oyster shells: Wash the oyster shells and crush them into fragments with a particle size of 5 mm; put the oyster shell fragments into a hydrochloric acid solution with a concentration of 0.5 mol / L and soak for 2 hours, then rinse the acid - treated oyster shell fragments with clean water until neutral, and then put them into a sodium hydroxide solution with a concentration of 0.3 mol / L and soak for 1 hour. After soaking, rinse the oyster shell fragments with clean water again, and then dry them in an oven at 100°C until constant weight. Mixing of composite cementitious material: Weigh ordinary Portland cement, metakaolin, and silica fume in a ratio of 6:3:1, pour them into a forced - action mixer, and stir for 10 - 15 minutes to fully and evenly mix the three materials. Concrete mixing: Add the mixed composite cementitious material into a large mixer, then add water and water reducer, and stir at low speed for 3 - 5 minutes to form a uniform cement paste to obtain a concrete paste. Add modified oyster shells: Slowly add the prepared modified oyster shells into the well-stirred concrete slurry, and stir for 8 - 10 minutes to evenly coat the modified oyster shells in the slurry, forming a porous concrete slurry with certain fluidity and plasticity. Pour and mold: Pour the porous concrete slurry into a pre-prepared mold, and use the method of layered pouring with each layer thickness controlled at 4 - 6 cm. After pouring each layer, vibrate with a vibrating rod for 1 - 2 minutes. Curing: After pouring is completed, place the mold in a curing room with a temperature of 20 ± 2°C and a relative humidity greater than 90%. In the initial stage of curing (2 days), after removing the mold, the humidity can be appropriately reduced, but the concrete surface still needs to be kept moist. The total curing time is 10 days to obtain the vegetative porous ecological concrete product.

[0042] Comparative Example 3 A vegetative porous ecological concrete, the preparation method of the modified oyster shells in its raw materials is different from that of the modified oyster shells in Example 3. Specifically, by mass fraction, it is made from the following raw materials: Modified oyster shells: 1500 parts; Composite cementitious material: 250 parts; Water: 100 parts; Water reducing agent (naphthalene sulfonate formaldehyde polymer): 2 parts; Plant fiber (rice husk fiber, and crushed to a length of 2.5 mm): 15 parts; Water retaining agent (sodium polyacrylate): 3 parts; Butyl stearate: 5 parts.

[0043] The vegetative porous ecological concrete product is prepared by the following method: Preparation of modified oyster shells: Crush the oyster shells into fragments with a length and width of 1 cm, wash them, soak them in 1.5 mol / L magnesium chloride solution for 2 hours, fish them out and dry, then calcine at 350°C for 1.5 hours, cool and soak in water until saturated with water absorption, and finally dry to the saturated surface dry state. Mixing of composite cementitious materials: Weigh ordinary Portland cement, metakaolin, and silica fume in a ratio of 6:3:1, pour them into a forced mixer, and stir for 10 minutes to fully and evenly mix the three materials; among them, the strength grade of the ordinary Portland cement is 42.5. Premix plant fiber and water retaining agent: Put the crushed plant fiber and water retaining agent into a small mixer and stir at low speed for 5 - 8 minutes to initially mix them evenly. Concrete mixing: Add the mixed composite cementitious materials into a large mixer, then add water and water reducer, and first mix at low speed for 3 - 5 minutes to form a uniform cement paste; then add the pre - mixed plant fibers and water - retaining agent, and continue to mix for 5 - 8 minutes to make the plant fibers and water - retaining agent evenly distributed in the paste; finally, add butyl stearate and mix for 3 - 5 minutes to ensure that butyl stearate is fully dispersed and evenly mixed with other materials to obtain a concrete paste; Adding modified oyster shells: Slowly add the prepared modified oyster shells into the well - mixed concrete paste, and mix for 8 - 10 minutes to make the modified oyster shells evenly wrap the paste, forming a porous concrete paste with certain fluidity and plasticity; Pouring and molding: Pour the porous concrete paste into a pre - prepared mold, and adopt the method of layered pouring, with the thickness of each layer controlled at 4 - 6 cm, and vibrate for 1 - 2 minutes with a vibrator after each layer is poured; Curing: After pouring is completed, place the mold in a curing room with a temperature of 20 ± 2 °C and a relative humidity greater than 90% for curing. In the initial stage of curing (2 days), after taking out and removing the mold, the humidity can be appropriately reduced, but the surface of the concrete still needs to be kept moist. The total curing time is 10 days to obtain the vegetative porous ecological concrete products.

[0044] The difference between the present invention and Comparative Example 3 is that in the present invention, the collected oyster shells are preliminarily cleaned to remove the impurities and dirt on the surface, and then broken into fragments with a particle size of about 5 - 10 mm. The oyster shell fragments are immersed in a hydrochloric acid solution with a concentration of 0.5 - 1 mol / L for 2 - 3 hours. This process can remove part of the calcium carbonate on the surface of the oyster shells, dissolve some impurities at the same time, and increase the surface porosity. Then, the acid - treated oyster shell fragments are rinsed with clean water until neutral, and then immersed in a sodium hydroxide solution with a concentration of 0.3 - 0.5 mol / L for 1 - 2 hours to change the chemical composition on the surface of the oyster shells and enhance their affinity with butyl stearate. After the immersion is completed, the oyster shell fragments are rinsed with clean water again, and then dried in an oven at 100 - 120 °C until constant weight. This method of acid - base synergistic modification can not only adjust the pH value of the oyster shells, but also improve their surface properties, making them better combine with butyl stearate, and is expected to improve the comprehensive performance of the vegetative porous ecological concrete.

[0045] Test 1 Performance test of vegetative porous ecological concrete I. Porosity test (I) Test process Specimen preparation: According to the formulations and preparation methods of Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3, cubic specimens with a side length of 100 mm were made, 10 for each type. During the production process, the measurement, mixing, and curing conditions of raw materials were strictly controlled to ensure the consistency of specimen quality.

[0046] Measurement method: First, the specimens were dried in an oven at 105 °C until constant weight and then cooled to room temperature.

[0047] Measured by the drainage method: The water bucket was filled with water, and the specimen was slowly placed into the water bucket full of water. The water overflowing from the water bucket was collected, and the volume of the water overflowing from the water bucket was measured with a measuring tube.

[0048] The apparent volume of the specimen was calculated by measuring the geometric dimensions, and the result was recorded as V1; the volume of the water overflowing from the water bucket was V2.

[0049] Subtract the volume of the water overflowing from the water bucket V2 from the apparent volume V1, and then divide the result by the apparent volume V1, which is the effective porosity (semi-open and connected pores) of the specimen. The formula is: Effective porosity = ((V1 - V2) / V1) × 100%. The porosity of each specimen was calculated, and the results are shown in Table 1.

[0050] Table 1: Group Porosity (%) Analysis Example 1 30.2–35.5 The porous structure of the modified oyster shell itself and the addition of rice husk fibers increase the number and connectivity of pores. Although butyl stearate does not directly increase the porosity, it helps to maintain the stability of the pore structure and prevent the pores from being blocked during the preparation process. Example 2 29.1–35.3 The preparation method is the same as that of Example 1. Within the appropriate dosage range of the raw materials, the porosity has little effect. Example 3 33.4–38.6 The raw materials and dosages are the same as those of Example 2, and the preparation method is improved to enable the components such as modified oyster shell, rice husk fiber, butyl stearate, and sodium polyacrylate to play their roles fully. After the modified oyster shell is treated specifically, its porous structure is more conducive to the formation of abundant pores, and the uniform dispersion of rice husk fibers enhances the pore connectivity. The porosity reaches a relatively high level, creating good spatial conditions for the growth of plant roots. Control Example 1 18.3–22.2 Lacking butyl stearate and rice husk fibers, it is impossible to effectively increase and stabilize the pore structure. It is difficult to form sufficient and stable pores only relying on the modified oyster shell, resulting in a lower porosity, which is not conducive to the extension and growth of plant roots. Control Example 2 20.6–24.8 Lacking butyl stearate and rice husk fibers, the stability and connectivity of the pore structure are insufficient. Compared with the examples, the porosity is significantly reduced, affecting the growth environment of plant roots in the concrete. Control Example 3 25.4–28.9 The preparation method of the modified oyster shell is different, and its pore structure and properties change. Although there are components such as rice husk fibers, the overall porosity is still lower than that of Example 3, indicating that the preparation method of the modified oyster shell has an important impact on the final porosity of the concrete. II. Compressive strength test (I) Test process Specimen preparation: Use the cubic specimens with a side length of 100 mm made above.

[0051] Test equipment: A pressure testing machine was used for the compressive strength test.

[0052] Loading method: Place the specimen at the center position of the pressure plate of the pressure testing machine, and continuously and uniformly apply pressure to the specimen at a rate of 0.3 MPa / s - 0.5 MPa / s until the specimen fails, and record the failure load F.

[0053] Calculate the compressive strength: According to the formula compressive strength f = F / A (A is the bearing area of the specimen. For a cubic specimen with a side length of 100 mm, A = 100 × 100 mm 2 = 10000 mm 2 = 0.01 m 2 ), calculate the compressive strength of each specimen, and the results are shown in Table 2.

[0054] Table 2: Group Compressive Strength (MPa) Analysis Example 1 6.3–9.0 The composite cementitious material provides basic strength support. The modified oyster shell participates in the formation of the concrete skeleton structure to a certain extent. Butyl stearate improves the compactness of the internal structure of the concrete, and the rice husk fiber plays a certain role in enhancing toughness. The preparation method of Example 1 enables the components to work synergistically, obtaining good compressive strength while ensuring a certain porosity. Example 2 5.5–8.0 The difference in the dosage of raw materials may affect the binding tightness and structure formation among the components, resulting in a slightly lower compressive strength than that of Example 1, but still meeting the strength requirements for use as a plant culture medium in general scenarios. Example 3 7.7-9.3 The optimized preparation process enables the composite cementitious material to react and combine fully with components such as modified oyster shell and rice husk fiber. Butyl stearate further optimizes the internal microstructure of the concrete, improves the density, making the compressive strength reach a relatively high level on the premise of ensuring that the porosity meets the plant growth requirements, and enhancing the stability and durability of the concrete products. Control Example 1 4.5-5.5 Lacking butyl stearate, rice husk fibers and sodium polyacrylate, the internal structure of the concrete is loose, unable to form an effective load-bearing skeleton, and the role of the modified oyster shell cannot be fully exerted. The compressive strength is low, difficult to bear large external forces, and prone to structural damage in practical applications. Control Example 2 4.3-5.5 Lacking butyl stearate and rice husk fibers, the internal structure and properties of the concrete are affected. Although other components provide certain strength, the overall compressive strength is still lower than that of the examples, restricting its application in scenarios with higher strength requirements. Control Example 3 5.5-6.5 The change in the preparation method of modified oyster shells affects their synergistic effect with other components, resulting in changes in the internal structure of the concrete and a compressive strength lower than that of Example 3, indicating that the preparation method of modified oyster shells has an impact on the compressive strength of the concrete. III. Air permeability test (I) Test process Specimen preparation: Cylindrical specimens with a diameter of 100 mm and a height of 50 mm were made, and 10 specimens were made for each formula and preparation method.

[0055] Testing device: A gas permeameter was used for the air permeability test.

[0056] Testing process: The specimen was installed in the test chamber of the gas permeameter to ensure good sealing between the specimen and the test chamber. Air at a certain pressure was introduced into the test chamber, and the air flow rate Q passing through the specimen per unit time was measured. The results are shown in Table 3.

[0057] Table 3: Group Air flow rate Q (cm³ / min) Analysis Example 1 61-70 The interconnected pores formed by the porous structure of modified oyster shells and rice husk fibers provide a channel for air circulation. Butyl stearate reduces the surface energy of the pore surface, making it difficult for water to accumulate and block the pores, ensuring smooth air circulation. Example 2 58-74 The preparation method is the same as that of Example 1. Within the appropriate dosage range of raw materials, there are slight differences in the uniformity and connectivity of the pore structure. Example 3 73-85 Optimizing the preparation method further optimizes the pore structure. The synergistic effect of modified oyster shells and rice husk fibers forms a richer and more interconnected pore channel. Butyl stearate effectively maintains the air permeability of the pores, enabling the air flow rate to reach a relatively high level and creating a good air-permeable environment for plant roots. Control Example 1 34-42 Lacking butyl stearate, rice husk fibers, and water retention agent, the pore structure is underdeveloped and poorly connected, making it difficult for air to circulate inside the concrete, resulting in poor air permeability, difficult to supply oxygen to plant roots, and affecting plant growth. Control Example 2 39-50 Lacking butyl stearate and rice husk fibers, the connectivity and air permeability of the pores are greatly affected. Control Example 3 52-61 After the change in the preparation method of modified oyster shells, the change in the pore structure affects air circulation. Although the role of rice husk fibers, the air permeability is still inferior to that of Example 3, indicating that the preparation of modified oyster shells also has an impact on the air permeability of the concrete. IV. Water retention test (I) Test process Specimen production: Cubic specimens with a side length of 100 mm were made, and 10 specimens were made for each type.

[0058] Saturated water absorption: The specimens were immersed in water for 48 hours to make them fully saturated with water, then taken out, the surface water was wiped off with a wet cloth, and the mass m was immediately weighed. 1 .

[0059] Drying process: The specimens were placed in an environment with a temperature of 20 °C and a relative humidity of 60% for drying. The mass of the specimens was weighed every 24 hours, and the mass m was recorded. 2 .

[0060] Calculation of water retention rate: According to the formula water retention rate = (m 2 / m 1 ) × 100%, the water retention rates at different time points were calculated. The results are shown in Table 4.

[0061] Table 4: Group Water retention rate after drying for 24 hours (%) Water retention rate after drying for 48 hours (%) Analysis Example 1 81-85 70-74 The porous structure of modified oyster shells and rice husk fibers increase the water storage space. Sodium polyacrylate water retention agent plays an efficient water retention role, and butyl stearate helps prevent water from evaporating too quickly. Example 2 78-86 69-75 The preparation method is the same as that of Example 1. Within the appropriate dosage range of raw materials, there are slight differences in water retention. Example 3 85-90 75-81 The optimized formula and preparation method enable the water retention agent to be fully combined with other components. The pore structure formed by modified oyster shells and rice husk fibers is more conducive to water storage and retention. Butyl stearate further enhances the waterproof performance, and the water retention rate is the highest among all examples, providing a more stable water supply for plant growth. Control Example 1 51-60 35-46 Lacking butyl stearate, rice husk fibers, and sodium polyacrylate, the concrete has almost no effective water retention mechanism, water is easy to lose, the water retention rate is very low, and it is difficult to meet the continuous water demand for plant growth. Control Example 2 59-70 45-54 Lacking butyl stearate and rice husk fibers, the role of the water retention agent cannot be fully exerted, the water retention performance of the concrete is poor, and water is lost quickly in a dry environment, making it difficult to ensure the water required for plant growth. Control Example 3 71-77 56-68 The change in the preparation method of modified oyster shells affects their synergistic water retention effect with other components. Although there are water retention agent and rice husk fibers, the water retention rate is still lower than that of Example 3, indicating that the preparation method of modified oyster shells has a greater impact on the water retention of the concrete. From the above test data results, it can be seen that the vegetative porous ecological concrete of the present invention has a good coordination effect among porosity, compressive strength, air permeability and water retention, specifically as follows: The porosity of Examples 1-3 of the present invention reaches 29.1% - 38.6%, which is significantly higher than that of Comparative Examples 1-3 (18.3% - 28.9%). The porous structure of the modified oyster shell itself and the addition of rice husk fibers increase the number and connectivity of pores, providing sufficient space for the growth of plant roots, helping the roots to stretch and absorb nutrients. Butyl stearate maintains the stability of the pore structure, prevents pore blockage, and ensures the normal growth environment of plant roots.

[0062] The compressive strength of Examples 1-3 was between 5.5–9.3 MPa, higher than that of Comparative Examples 1-3 (4.3–6.5 MPa). The composite cementitious material, modified oyster shell, butyl stearate, and rice husk fiber worked synergistically to improve the compressive strength of the concrete while ensuring that the porosity met the requirements for plant growth. This enabled the vegetative porous ecological concrete to withstand certain external forces when used as a plant growth medium, making it less likely to deform or be damaged, and ensuring the stability of the plant growth environment.

[0063] In terms of air permeability, the air flow rate Q of Examples 1-3 was 58-85 cm³ / min, significantly higher than that of Comparative Examples 1-3 (34-61 cm³ / min). The porous structure of the modified oyster shell and the interconnected pores formed by the rice husk fiber, along with the role of butyl stearate in reducing the surface energy of the pores to prevent water from blocking the pores, made the concrete have good air permeability, which could provide sufficient oxygen for the plant roots, meet the needs of root respiration, and promote the healthy growth of plants.

[0064] In the water retention test, the water retention rates of Examples 1-3 after 24 hours of drying were 78%-90%, and after 48 hours of drying were 69%-81%, much higher than those of Comparative Examples 1-3 (51%-77% after 24 hours of drying and 35%-68% after 48 hours of drying). The synergistic effect of the modified oyster shell, rice husk fiber, and sodium polyacrylate water retaining agent increased the water storage space, and butyl stearate helped prevent water from evaporating too quickly, enabling the concrete to retain water for a longer time in a dry environment and providing a continuous and stable water source for plant growth.

[0065] Experiment 2 Experimental preparation: Select 5 flower pots of the same specification, and label them as Example 2 pot, Example 3 pot, Comparative Example 1 pot, Comparative Example 2 pot, and Comparative Example 3 pot. Fill each flower pot with the vegetative porous ecological concrete prepared according to the corresponding example and comparative example, and reserve planting pits of the same size on the vegetative porous ecological concrete products. Prepare several petunia seedlings with similar growth conditions and 3-4 true leaves.

[0066] Planting process: Carefully transplant the petunia seedlings into the planting pits, fill the soil and compact it to ensure that the roots of the seedlings are in full contact with the concrete. Place the flower pots in the same greenhouse environment, control the temperature at 20-25°C, the light time at 12-14 hours per day, water regularly and quantitatively, with a watering amount of 200 mL each time, and keep the concrete moist but without waterlogging.

[0067] Monitoring of growth indicators and data recording Transplanting survival rate (7 days after transplanting) Example 2 Pot: 93%. The vegetative porous ecological concrete of Example 2 has good pore structure and water retention and air permeability. The modified oyster shells, rice husk fibers and sodium polyacrylate act synergistically to provide a suitable environment for petunia seedlings. Butyl stearate helps maintain pore stability and improve the transplanting survival rate.

[0068] Example 3 Pot: 95%. Optimize the preparation method to balance and coordinate the performance of the concrete. The modified oyster shells provide abundant pores and certain nutrients. The rice husk fibers increase the porosity and air permeability. Sodium polyacrylate ensures water supply. Butyl stearate stabilizes the pores, and the transplanting survival rate is the highest.

[0069] Control Example 1 Pot: 61%. Lacking butyl stearate, rice husk fibers and sodium polyacrylate, the concrete has poor porosity, air permeability and water retention, the root growth is restricted, and the transplanting survival rate is low.

[0070] Control Example 2 Pot: 70%. Lacking butyl stearate and rice husk fibers, the pore structure and air permeability are not good. Although there is sodium polyacrylate for water retention, the overall environment is not conducive to root growth, and the survival rate is relatively low.

[0071] Control Example 3 Pot: 86%. The preparation method of the modified oyster shells is different, its pore structure and performance change, which affects the comprehensive performance of the concrete. Although other components are the same, the overall is not as good as Example 3, and the survival rate is relatively low.

[0072] Plant height growth amount (30 days after transplanting) Example 2 Pot: Increase by 7 - 9 cm. The appropriate porosity and good water retention and air permeability enable the petunia roots to fully absorb nutrients and water, promoting the growth of the above-ground part.

[0073] Example 3 Pot: Increase by 8 - 10 cm. The components and preparation method work synergistically to provide the best conditions for plant growth, and the plant height increases the most.

[0074] Control Example 1 Pot: Increase by 3 - 5 cm. Due to the lack of key components, the concrete has poor performance, the plant grows slowly, and the plant height increases little.

[0075] Control Example 2 Pot: Increase by 4 - 6 cm. The lack of butyl stearate and rice husk fibers affects the pore structure and air permeability, the plant growth is restricted, and the plant height increases less.

[0076] Control Example 3 Pot: Increase by 6 - 8 cm. The change in the performance of the modified oyster shells affects the overall performance of the concrete, the plant growth is not as good as that in Example 3, and the plant height increases relatively less.

[0077] Change in the number of leaves (40 days after transplanting) Example 2 Pot: The number of leaves increases by 5 - 7. The good growth environment promotes leaf differentiation and growth.

[0078] Example 3 Pot: The number of leaves increased by 6 - 8. Each component synergistically optimized the growth environment, and the leaves grew well.

[0079] Comparative Example 1 Pot: The number of leaves increased by 2 - 4. The performance of the concrete was poor and could not meet the growth requirements of the plants, so the leaves grew slowly.

[0080] Comparative Example 2 Pot: The number of leaves increased by 3 - 5. The pore structure and air permeability problems restricted the growth of the plants, and the increase in the number of leaves was less.

[0081] Comparative Example 3 Pot: The number of leaves increased by 4 - 6. The change in the performance of the modified oyster shell affected the growth of the plants, and the increase in the number of leaves was not as good as that in Example 3.

[0082] Flowering time and number of flowers (60 days after transplantation) Example 2 Pot: Flowering started about 42 days after transplantation, and the average number of flowers per plant was 5 - 7. The plants grew vigorously, with sufficient nutrient accumulation, and flower bud differentiation and flowering were smooth.

[0083] Example 3 Pot: Flowering started about 40 days after transplantation, and the average number of flowers per plant was 6 - 8. The optimized concrete performance enabled the plants to grow well, with early flowering and a large number of flowers.

[0084] Comparative Example 1 Pot: Flowering started about 55 days after transplantation, and the average number of flowers per plant was 2 - 4. The plants grew poorly, with delayed flowering and a small number of flowers.

[0085] Comparative Example 2 Pot: Flowering started about 50 days after transplantation, and the average number of flowers per plant was 3 - 5. The pore structure and air permeability problems affected the growth and flower bud differentiation of the plants, and the flowering situation was not good.

[0086] Comparative Example 3 Pot: Flowering started about 47 days after transplantation, and the average number of flowers per plant was 5 - 6. The change in the performance of the modified oyster shell affected the flowering of the plants, and the flowering time and number of flowers were not as good as those in Example 3.

[0087] Experiment 3 I. Experimental Preparation Experimental materials and equipment: Prepare sufficient amounts of vegetation - type porous ecological concrete prepared according to Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3, and reserve planting pits of the same size on the vegetation - type porous ecological concrete products. Select 25 Clivia miniata seedlings with similar growth conditions, healthy and having 5 - 6 leaves. Prepare 5 flower pots of the same specification and made of terracotta. The terracotta flower pots have good air permeability and can reduce the interference of the flower pot material on the experiment. Prepare experimental equipment such as a greenhouse with controllable temperature and humidity, temperature and humidity sensors, soil moisture sensors, vernier calipers, and electronic scales.

[0088] Experimental grouping: Five flowerpots were respectively labeled as the Example 2 group, the Example 3 group, the Comparative Example 1 group, the Comparative Example 2 group, and the Comparative Example 3 group. Each group of flowerpots was filled with the corresponding vegetative porous ecological concrete, and 5 Clivia seedlings were transplanted into each group. When transplanting, ensure that the roots of the seedlings are stretched, the planting depth is consistent, and an appropriate amount of root-fixing water is watered.

[0089] II. Experimental process Simulation of climate environment setting: Simulate extreme climate conditions of high temperature (35°C) in summer and drought (stopping watering for 10 days) in the greenhouse. Each climate condition lasts for 10 days, and then the normal greenhouse environment (temperature 20 - 25°C, relative humidity 60% - 70%) is restored for 5 days, and then the next extreme climate simulation is carried out. The entire experimental cycle is 90 days.

[0090] Monitoring of growth indicators: During the experiment, the temperature and humidity around the flowerpots were measured regularly every day with a temperature and humidity sensor, and the water content of the concrete substrate was measured with a soil moisture sensor. Every 10 days, the length of the Clivia leaves was measured with a vernier caliper, the weight of the plants was measured with an electronic scale, and the growth conditions such as leaf color, luster, and whether there are pests and diseases were observed and recorded. During the simulation of extreme climate, the response of Clivia to temperature and water changes was observed emphatically.

[0091] III. Test comparison Experiment on high temperature (35°C) in summer: Leaf growth data: In the Example 2 group, the average increase in leaf length was 0.8 - 1.2 cm, and the leaf color was emerald green and shiny; in the Example 3 group, the average leaf increase was 1.0 - 1.4 cm, and the leaf state was good. In the Comparative Example 1 group (without butyl stearate, rice husk fiber, and sodium polyacrylate), the average increase in leaf length was 0.3 - 0.5 cm, and the yellowing area of the leaves accounted for 15% - 21%; in the Comparative Example 2 group (without butyl stearate and rice husk fiber), the average leaf increase was 0.4 - 0.6 cm, and the yellowing area accounted for 12% - 16%; in the Comparative Example 3 group (with different preparation methods of modified oyster shells), the average leaf increase was 0.5 - 0.8 cm, and the edges of the leaves were yellowing.

[0092] Change in plant weight: In the Example 2 group, the average weight gain of the plants was 51 - 69 g; in the Example 3 group, the weight gain was 58 - 80 g. In the Comparative Example 1 group, the average weight gain of the plants was 21 - 30 g; in the Comparative Example 2 group, the weight gain was 27 - 39 g; in the Comparative Example 3 group, the weight gain was 43 - 52 g.

[0093] Experiment on drought (stopping watering for 10 days): Leaf water content: In the Example 2 group, the leaf water content remained at 65% - 71%; in the Example 3 group, it was 70% - 75%. In the Comparative Example 1 group, the leaf water content dropped to 44% - 50%; in the Comparative Example 2 group, it was 51% - 55%; in the Comparative Example 3 group, it was 56% - 65%.

[0094] Plant growth stagnation situation: In Example 2 group, the plants grew basically normally without obvious growth stagnation; in Example 3 group, the growth was less affected. In Comparative Example 1 group, the plant growth was significantly stagnated; in Comparative Example 2 group, the growth stagnation was more obvious; in Comparative Example 3 group, the growth also showed a certain degree of stagnation.

[0095] It can be seen from the above experimental data that in high temperature in summer, in Example 2 - 3 groups containing butyl stearate, due to its stable pore structure to ensure heat dissipation, the leaf growth and plant weight gain of Clivia miniata were significantly better than those in the comparative example groups. Under drought conditions, butyl stearate combined with other components ensured pore air permeability and reduced water accumulation. The leaf water content in the example groups was higher and the plant growth was less affected. This fully demonstrated that butyl stearate in the vegetation - type porous ecological concrete played an important role in the growth of Clivia miniata under extreme climates by affecting the surface properties of pores and indirectly assisting in temperature regulation.

[0096] Test 4 A vegetation - type porous ecological concrete with a surface protective coating, on which an organosilicon waterproof coating is sprayed on the surface of the vegetation - type porous ecological concrete in Example 3. The solid content of the organosilicon waterproof coating is 30% - 50%, the viscosity is 10 - 50 mPa·s (25°C), and the spraying amount is 0.2 - 0.5 kg / m²; the organosilicon waterproof coating can form a continuous and dense protective film on the concrete surface. The thickness of this protective film is 0.1 - 0.3 mm, which can effectively block the direct scouring of rainwater, reduce the water absorption rate of the concrete to about 5% after continuous rain for 24 hours, reduce the entry of water into the concrete interior, and reduce the risk of nutrient loss and pore blockage. At the same time, after continuous irradiation for 1000 hours under the condition that the ultraviolet radiation intensity is 5000 μW / cm², the degree of powdering and discoloration on the concrete surface does not exceed Grade 1, effectively reducing the damage of ultraviolet rays to the concrete and delaying its aging speed.

[0097] Test 5 A surface-hardened vegetation-type porous ecological concrete, which uses silane impregnation treatment to harden the surface of the vegetation-type porous ecological concrete in Example 3. The silane used is isobutyltriethoxysilane, the concentration of the silane solution is 80% - 95%, and the impregnation depth is 3 - 5 mm; the silane reacts with moisture inside the concrete to form silanol, and then a waterproof and water-repellent layer is formed. This waterproof and water-repellent layer makes the static water contact angle on the concrete surface reach 100° - 120°. After the standard freeze-thaw cycle test (-20°C to 20°C, 8 hours for each cycle, and a total of 50 cycles), the mass loss rate of the concrete does not exceed 2%, and the compressive strength loss rate does not exceed 10%, effectively improving the durability and frost resistance of the concrete; at the same time, after surface carbonization treatment (the specific operation steps of surface carbonization treatment are: place the concrete in a closed carbonization reaction chamber, introduce carbon dioxide gas with a concentration of 15% - 25% into the chamber, control the temperature in the reaction chamber at 20°C - 30°C, and the relative humidity at 60% - 70%, and the carbonization reaction time lasts for 48 - 72 hours. The thickness of the carbonized layer formed on the concrete surface after carbonization is 2 - 4 mm;), the thickness of the carbonized layer formed on the concrete surface is 2 - 4 mm. This carbonized layer can make the mass loss rate of the concrete not exceed 5% after being soaked in 10% sulfuric acid solution for 30 days, enhancing the corrosion resistance of the concrete.

[0098] The test results of Test 4 and Test 5 show that the present invention is also expected to solve the problem of the long-term performance stability of the vegetation-type porous ecological concrete: during long-term use, the vegetation-type porous ecological concrete may be affected by the combined action of natural environmental factors (such as rainwater scouring, freeze-thaw cycles, ultraviolet radiation, etc.) and biological factors (plant root growth penetration, microbial erosion, etc.). Rainwater scouring may lead to the loss of nutrients and pore blockage in the concrete; freeze-thaw cycles will generate stress inside the concrete, causing structural damage; plant root growth may damage the pore structure of the concrete, affecting its strength and stability, etc. Therefore, the design of the present invention is expected to be popularized and applied in projects with higher durability requirements, broadening the application needs.

[0099] Although the embodiments of the present invention have been disclosed as above, it is not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved.

Claims

1. A vegetative porous ecological concrete, characterized in that: It is made of the following raw materials by weight: Modified oyster shell: 1200~1500 parts; Composite cementitious material: 250~350 parts; Water: 100~130 parts; Water reducing agent: 2~3 parts; Plant fiber: 15-25 parts; Water retaining agent: 3~5 parts; Butyl stearate: 5~10 parts.

2. The vegetation-growing porous ecological concrete according to claim 1, characterized in that: The preparation method of the modified oyster shell is as follows: the oyster shell is cleaned and crushed into fragments with a particle size of 5-10 mm; the oyster shell fragments are soaked in a hydrochloric acid solution with a concentration of 0.5-1 mol / L for 2-3 hours, and then the acid-treated oyster shell fragments are rinsed with clean water until neutral, and then soaked in a sodium hydroxide solution with a concentration of 0.3-0.5 mol / L for 1-2 hours. After the soaking, the oyster shell fragments are rinsed with clean water again, and then dried in an oven at 100-120° C. to constant weight.

3. The vegetation-based porous ecological concrete according to claim 1, characterized in that: The composite cementitious material is prepared by mixing ordinary Portland cement, metakaolin and silica fume in a ratio of 6:3:1, wherein the strength grade of the ordinary Portland cement is 42.

5.

4. The vegetation-growing porous ecological concrete according to claim 1, characterized in that: The water reducing agent is naphthalenesulfonate formaldehyde polymer.

5. The vegetation-growing porous ecological concrete according to claim 1, characterized in that: The plant fiber is one or more of rice husk fiber and coconut fiber, and is crushed to a length of 2.5-8 mm.

6. The vegetation-growing porous ecological concrete according to claim 1, characterized in that: The water retaining agent is sodium polyacrylate.

7. A method for preparing the vegetation-type porous ecological concrete according to any one of claims 1 to 6, characterized in that: The following steps are involved: Premixing plant fiber and water retaining agent: Mix the plant fiber and water retaining agent evenly; Concrete mixing: Mix the composite cementitious material, water and water reducing agent to form a uniform cement paste; then add the premixed plant fiber and water retaining agent, and continue to stir to evenly distribute the plant fiber and water retaining agent in the paste; finally, add butyl stearate, stir to ensure that butyl stearate is fully dispersed and evenly mixed to obtain concrete paste; Adding modified oyster shells: adding the modified oyster shells into the stirred concrete slurry, stirring so that the modified oyster shells are evenly wrapped in the slurry to form a porous concrete slurry; Casting and molding: Pour the porous concrete slurry into the mold, and then place the mold in a curing room for curing to obtain a vegetation-type porous ecological concrete product.

8. An application of the vegetative porous ecological concrete as claimed in any one of claims 1 to 6, characterized in that: The vegetative porous ecological concrete is applied to garden landscaping, slope protection greening, and roof greening as a plant culture matrix.

9. A vegetated porous ecological concrete with a surface protective coating, characterized in that: An organic silicon waterproof coating is sprayed on the surface of the vegetation-type porous ecological concrete as described in claim 7, wherein the solid content of the organic silicon waterproof coating is 30% to 50%, the viscosity is 10 to 50 mPa·s, and the spraying amount is 0.2 to 0.5 kg / m² at 25°C; the organic silicon waterproof coating can form a continuous and dense protective film on the concrete surface, and the thickness of the protective film is 0.1 to 0.3 mm.

10. A surface hardened porous ecological concrete, characterized in that: The surface of the vegetative porous ecological concrete as described in claim 7 is hardened by silane impregnation treatment, the silane used is isobutyltriethoxysilane, the concentration of the silane solution is 80%~95%, and the impregnation depth is 3~5 mm; the silane reacts with water inside the concrete to generate silanol, and then forms a waterproof and hydrophobic layer, which makes the static water contact angle of the concrete surface reach 100°~120°, and after surface carbonization treatment, the thickness of the carbonized layer formed on the concrete surface is 2~4 mm.