Ecological slope protection porous ecological material with good toughness and durability and preparation method thereof

Abstract

The application discloses an ecological slope protection porous ecological material with good toughness and durability and a preparation method thereof. The ecological slope protection porous ecological material is ecological porous water-permeable concrete based on recycled aggregate and modified corn cob aggregate, and is mainly composed of recycled aggregate 45-67%, modified corn cob aggregate 3-15%, cement 21-28% and water 9-12%. First, the recycled aggregate, the modified corn cob aggregate and part of the water are stirred and mixed, then the cement and the remaining water are added and continuously stirred and mixed to obtain the ecological porous water-permeable concrete based on the recycled aggregate and the modified corn cob aggregate; finally, the ecological porous water-permeable concrete is obtained by uniformly loading into a prefabricated mold and curing and forming. Through the technical scheme, the problem of low plant coverage and consumption of natural aggregate in river slope protection can be solved, and the weak point of the prior art in the research on the plant adaptability and corn cob building material utilization of the slope protection is overcome.

Description

A porous ecological material for slope protection with good toughness and durability and its preparation method Technical Field 1. Technical Field:

[0001] This invention belongs to the field of hydraulic ecological materials technology, and relates to a technology for configuring porous ecological materials for ecological slope protection, specifically to a porous ecological material for ecological slope protection with good toughness and durability and its preparation method. Background Technology II. Background Technology:

[0002] Existing methods for riverbank protection can be broadly categorized into three types: First, reinforcing riverbanks by laying self-compacting concrete slabs; second, reinforcing riverbanks using iron cages or hollow precast concrete components, which can be filled with large natural rocks; and third, reinforcing riverbanks using precast concrete components with hexagonal prism-shaped internal spaces, which can be planted with vegetation. However, none of these methods can achieve a high vegetation coverage rate for riverbanks. Furthermore, in my country, a large amount of agricultural waste, such as corn cobs, is incinerated or landfilled annually, with only a small portion used in light industry and food manufacturing. The application of corn cobs processed into building materials in the field of eco-friendly concrete remains largely unexplored. The large-scale incineration and landfilling of corn cobs contributes almost nothing to the economy and causes numerous environmental and social problems.

[0003] Currently, there are also some patent documents related to ecological slope protection. For example, invention patent CN216865197U discloses a three-dimensional ecological slope protection for gardens with rainwater filtration and soil stabilization functions. The technology involves installing a frame inside the slope. The upper surface of the frame has several planting grids, the lower surface of the planting grids has a vegetation layer, the vegetation layer has a soil layer, the lower surface of the soil layer has a sand and gravel layer, a fabric layer is placed on the lower surface of the sand and gravel layer, and a first filter screen is installed on the lower surface of the fabric layer. The two ends of the first filter screen are connected to the two ends of the lower surface of the frame. A water tank is connected to the lower surface of the frame, and a second filter screen is embedded in the inner surface of the water tank. The lower surface of the first filter screen and the upper surface of the second filter screen cooperate to form a buffer zone. This technical solution focuses on disclosing a three-dimensional ecological slope protection for gardens with rainwater filtration and soil stabilization functions, solving the problem of the lack of rainwater filtration in existing systems, but it does not consider the issue of plant growth and coverage. 2. Invention patent CN110521503A discloses a wet-sprayed vegetation concrete ecological slope protection technology. The base layer construction mix ratio (per cubic meter of freshly mixed substrate) and preparation method are: 0.2-0.6 m³ of loam. 3 Organic matter 0.1-0.15m 3The surface layer consists of: 20-50 kg of cement, 15-40 kg of wet-sprayed vegetation concrete additive, 0.4-0.8 kg of slow-release fertilizer, 0.3-0.7 kg of ordinary compound fertilizer, and 0.1-0.3 kg of soil binder; wherein, the organic matter comprises 40-50% by volume of grass fiber and 50-60% by volume of decomposed rice husks or distiller's grains; the grass fiber uses chopped rice straw or wheat straw with a length of 20-80 mm; the surface layer includes loam, cement, wet-sprayed vegetation concrete additive, ordinary compound fertilizer, slow-release fertilizer, soil binder, organic matter, and plant seeds. The construction mix ratio (per cubic meter of freshly mixed substrate) and preparation method for the surface layer is: 0.2-0.6 m³ of loam. 3 Organic matter 0.1-0.2m 3 The ingredients include: 0-30 kg of cement, 0-25 kg of wet-sprayed vegetation concrete additive, 0.5-0.8 kg of ordinary compound fertilizer, 0.4-1.2 kg of slow-release fertilizer, 0.2-0.3 kg of soil binder, and 100-200 g of plant seeds. The ratio of herbaceous to shrub seeds in the plant seeds is 2-3:1-2. The organic matter contains 20-40% grass fiber and 60-80% rotten rice husks or distiller's grains. The grass fiber should be 20-80 mm long chopped rice or wheat straw. This technical solution focuses on a wet-sprayed vegetation concrete ecological slope protection technology that can adhere well to steep slopes. It overcomes the problems of low efficiency, high dust pollution, and high risk of spraying construction in existing dry-spraying vegetation concrete processes. It also considers both plant growth coverage and the reuse of plant by-products. However, it does not consider the durability of the ecological slope protection in practical applications. III. Summary of the Invention:

[0004] The technical problem this invention aims to solve is as follows: In view of the current state of research and development and existing problems of ecological slope protection technology, this invention provides a porous ecological material for slope protection with good toughness and durability, and its preparation method. Through this invention, the weaknesses of existing technologies in the research on the adaptability of slope protection plants and the utilization of corn cobs as building materials can be overcome, and the problems of natural aggregate consumption and low plant coverage in riverbank protection can be solved.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] This invention provides an ecological porous ecological material for slope protection with good toughness and durability. The ecological porous ecological material is an ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate. Expressed by mass percentage, the ecological porous permeable concrete is mainly composed of 45-67% recycled aggregate, 3-15% modified corn cob aggregate, 21-28% cement and 9-12% water.

[0007] Based on the above-mentioned porous ecological slope protection material with good toughness and durability, the recycled aggregate is obtained by crushing waste concrete pavement, with two particle sizes: 4.75-9.5mm and 9.5-19mm; the modified corn cob aggregate is natural corn cob with a diameter of 4.75-9.5mm after treatment, and its compressive strength is 0.9MPa; the cement is PO 42.5 grade ordinary Portland cement.

[0008] Based on the aforementioned porous ecological material for slope protection with good toughness and durability, the processing method for the modified corn cob aggregate is as follows:

[0009] a. Place the sodium silicate solution and the cut natural corn cobs (4.75–9.5 mm) in a pressure impregnation tank, ensuring the natural corn cobs are completely immersed in the sodium silicate solution, and then seal the tank.

[0010] b. After sealing, extract the air to -0.1 to -0.5 MPa and maintain it for 10 to 15 minutes, then release the pressure to 0.5 to 2.0 MPa and maintain it for 20 to 30 minutes;

[0011] c. After repeating step b 3 to 6 times, remove the corn cob and wash it. After washing, let the corn cob stand (until the residual water on the surface of the corn cob no longer flows down in streams).

[0012] d. Place the corn cobs that have been left to stand into an oven at 120±5℃ and dry them for 6 to 12 hours.

[0013] e. Remove the dried corn cobs and place them in an indoor environment at 20±2℃ for cooling. The cooling time is 3 to 6 hours. After cooling, modified corn cob aggregate with a diameter of 4.75 to 9.5 mm is obtained.

[0014] Based on the above-mentioned porous ecological slope protection material with good toughness and durability, the sodium silicate solution in step a has an initial modulus of 3.3, a water content of 64.16%, and a Baume degree of 38.5°Bé.

[0015] In addition, a method for preparing a porous ecological material for slope protection with good toughness and durability is provided, the preparation method comprising the following steps:

[0016] 1) Weigh out all raw materials according to the above proportions for ecological porous permeable concrete;

[0017] 2) Pour the weighed recycled aggregate, modified corn cob aggregate and some water into the mixer in sequence and mix.

[0018] 3) Then add the weighed cement and the remaining water and continue to stir. After thorough stirring, you will get ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate.

[0019] 4) The ecological porous permeable concrete obtained in step 3) is evenly poured into the precast mold for curing and molding to obtain ecological porous permeable concrete.

[0020] According to the above-mentioned method for preparing porous ecological slope protection material with good toughness and durability, in step 2), the stirring temperature is room temperature, the stirring rate is 50-60 r / min, the stirring time is 20-30 s, and the water accounts for 40-50% of the water mass.

[0021] According to the above-mentioned method for preparing porous ecological slope protection material with good toughness and durability, in step 3), the stirring temperature is room temperature, the stirring rate is 50-60 r / min, and the stirring time is 2-3 min; the porosity of the resulting porous permeable ecological concrete is 30-35%.

[0022] According to the above-mentioned method for preparing porous ecological slope protection material with good toughness and durability, the curing temperature in step 4) is 18-22℃, the curing humidity is 93±2%, and the curing time is 28-56 days.

[0023] According to the above-mentioned method for preparing porous ecological slope protection material with good toughness and durability, the prefabricated mold in step 4) is a cubic specimen with a side length of 150mm.

[0024] Corn cobs are a byproduct of corn threshing. Due to the limited technology for processing corn cobs into building materials, they are usually incinerated or landfilled. However, on-site incineration leads to severe environmental pollution, while on-site landfill requires 8 months to 1 year for natural degradation, occupying large areas of land resources over a long period. This invention processes corn cobs into building materials to prepare modified corn cob aggregate. This modified corn cob aggregate is then used to prepare eco-friendly porous permeable concrete based on recycled aggregate and modified corn cob aggregate. During the preparation process, the amount of sodium silicate solution added and the preparation technique are key technologies. Only by ensuring the synergistic effect of each parameter can the invention achieve its intended technical effects.

[0025] The positive and beneficial effects of this invention are:

[0026] 1. In the ecological porous permeable concrete configuration technology based on recycled aggregate and modified corn cob aggregate of this invention, recycled aggregate and modified corn cob aggregate are used to replace natural aggregate, which improves the utilization rate of solid waste, reduces the consumption of natural resources, and improves the durability of ecological slope protection materials. The high continuous porosity, high vegetation pore size and low pH value pore environment enhance the plant adaptability of ecological slope protection, thereby overcoming the weaknesses of existing technologies in the research on the adaptability of slope protection plants and the building material utilization of corn cob, and solving the problems of natural aggregate consumption and low plant coverage in river slope protection.

[0027] 2. Compared with the prior art, the present invention uses corn cobs from agricultural waste and recycled aggregates from construction waste, and provides a plant growth environment with low alkalinity, high vegetation pore size and high continuous porosity, which not only improves the durability requirements of riverbank protection, but also meets the environment required for plant growth.

[0028] 3. The technical solution of this invention has undergone basic performance tests, including vegetation pore size testing, pore pH value testing, continuous porosity testing, 28-day compressive strength testing, frost resistance testing, and sulfate attack resistance testing. The results show that the ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate of this invention can well meet the various requirements of riverbank protection, improve the durability of ecological materials for slope protection, and thus solve the problem of the difficulty in resource utilization of large quantities of agricultural waste (corn cobs) and the long-term, large-scale land occupation caused by corn cob incineration or landfill.

[0029] 4. The ecological porous permeable concrete prepared using the technical solution of this invention has undergone relevant performance tests, and the test results are detailed in Table 1.

[0030] Table 1. Performance test results of the ecological porous permeable concrete prepared according to the present invention.

[0031]

[0032] Note: In Table 1, group 1 is the control example, and groups 2-5 are the ecological porous permeable concretes prepared in Examples 1-4 of this invention. Figure 4. Figure Description:

[0033] Figure 1 is a line graph showing the change in compressive strength of the ecological porous permeable concrete of the present invention under different curing times;

[0034] As shown in Figure 1, the compressive strength increases with the increase of curing time.

[0035] Figure 2 is a line graph showing the change in mass loss rate of the ecological porous permeable concrete of the present invention under different freeze-thaw cycles.

[0036] As shown in Figure 2, the mass loss rate increases with the number of freeze-thaw cycles, while the addition of corn cobs reduces the mass loss rate relatively.

[0037] Figure 3 is a line graph showing the change in compressive strength loss rate of the ecological porous permeable concrete of the present invention under different freeze-thaw cycles;

[0038] As shown in Figure 3, the compressive strength loss rate increases with the number of freeze-thaw cycles, while the addition of corn cobs relatively reduces the compressive strength loss rate.

[0039] Figure 4 is a line graph showing the change in mass loss rate of the ecological porous permeable concrete of the present invention under different number of wet-dry cycles of sulfate erosion.

[0040] As shown in Figure 4, as the number of dry and wet cycles increases, the mass loss first increases and then decreases. The addition of corn cobs keeps the mass loss rate at a low level or even eliminates the mass loss altogether.

[0041] Figure 5 is a line graph showing the change in compressive strength loss and corrosion resistance coefficient of the ecological porous permeable concrete of the present invention under different sulfate erosion wet-dry cycles;

[0042] As shown in Figure 5, the corrosion resistance coefficient first increases and then decreases with the increase of the number of wet and dry cycles. The addition of corn cob makes the corrosion resistance coefficient relatively high, and the higher corrosion resistance coefficient indicates a lower compressive strength loss rate. Detailed Implementation Method Five: Detailed Implementation Method

[0043] The present invention will be further illustrated below with reference to the embodiments, but this does not limit the scope of protection of the technical solution of the present invention.

[0044] Example 1:

[0045] This invention relates to an ecological porous permeable concrete for slope protection with good toughness and durability. The material is based on recycled aggregate and modified corn cob aggregate. Expressed by mass percentage, the ecological porous permeable concrete is composed of 67% recycled aggregate, 3% modified corn cob aggregate, 21% cement and 9% water.

[0046] The recycled aggregate is obtained by crushing waste concrete pavement, resulting in two particle sizes: 4.75–9.5 mm and 9.5–19 mm (the original strength grade of the waste concrete is C25–C30).

[0047] During the batching process, the recycled aggregates with particle sizes of 4.75–9.5 mm and 9.5–19 mm are in a mass ratio of 1:1.13.

[0048] The modified corn cob aggregate is natural corn cob with a diameter of 4.75–9.5 mm after treatment and a compressive strength of 0.9 MPa; the cement is PO 42.5 grade ordinary Portland cement;

[0049] The processing method for the modified corn cob aggregate is as follows:

[0050] a. Place the sodium silicate solution (initial modulus of sodium silicate solution is 3.3, water content is 64.16%, Baume degree is 38.5°Bé) and the cut natural corn cobs of 4.75-9.5mm in a pressure impregnation tank. The natural corn cobs are completely immersed in the sodium silicate solution, and then the tank is sealed.

[0051] b. After sealing, extract the air to -0.1MPa and maintain it for 10 minutes, then release the pressure to 0.5MPa and maintain it for 20 minutes;

[0052] c. After repeating step b 4 times, remove the corn cob and wash it. After washing, let the corn cob stand (until the residual water on the surface of the corn cob no longer flows down in streams).

[0053] d. Place the corn cobs that have been left to stand into an oven at 120±5℃ and dry them for 10 hours.

[0054] e. Remove the dried corn cobs and place them in an indoor environment at 20±2℃ for 5 hours to cool; after cooling, modified corn cob aggregate with a diameter of 4.75–9.5 mm is obtained.

[0055] Example 2: Basically the same as Example 1, except that:

[0056] This invention relates to an ecological porous permeable concrete for slope protection with good toughness and durability. The material is based on recycled aggregate and modified corn cob aggregate. The ecological porous permeable concrete is composed of 61% recycled aggregate, 6% modified corn cob aggregate, 23% cement and 10% water, expressed as a percentage by mass.

[0057] During the batching process, the recycled aggregates with particle sizes of 4.75–9.5 mm and 9.5–19 mm are mixed in a mass ratio of 1:0.74.

[0058] Example 3: Basically the same as Example 1, except that:

[0059] This invention relates to an ecological porous permeable concrete for slope protection with good toughness and durability. The material is based on recycled aggregate and modified corn cob aggregate. The ecological porous permeable concrete is composed of 54% recycled aggregate, 10% modified corn cob aggregate, 25% cement and 11% water, expressed as a percentage by mass.

[0060] During the batching process, the recycled aggregates with particle sizes of 4.75–9.5 mm and 9.5–19 mm are mixed in a mass ratio of 1:0.38.

[0061] Example 4: Basically the same as Example 1, except that:

[0062] This invention relates to an ecological porous permeable concrete for slope protection with good toughness and durability. The material is based on recycled aggregate and modified corn cob aggregate. The ecological porous permeable concrete is composed of 45% recycled aggregate, 15% modified corn cob aggregate, 28% cement and 12% water, expressed as a percentage by mass.

[0063] During the batching process, the recycled aggregates with particle sizes of 4.75–9.5 mm and 9.5–19 mm are mixed in a mass ratio of 1:0.

[0064] The preparation method of the porous ecological slope protection material with good toughness and durability described in any one of Embodiments 1-4 of the present invention comprises the following detailed steps:

[0065] 1) Weigh out all raw materials according to the proportions of the ecological porous permeable concrete described in any of Examples 1-4;

[0066] 2) Weigh out the recycled aggregate, modified corn cob aggregate and 45% water and pour them into the mixer in sequence for mixing;

[0067] The stirring temperature was room temperature, the stirring speed was 50-60 r / min, and the stirring time was 30 s.

[0068] 3) Then add the weighed cement and the remaining water and continue to stir. After thorough stirring, you will get ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate.

[0069] The mixing temperature was room temperature, the mixing speed was 50-60 r / min, and the mixing time was 3 min; the porosity of the resulting ecological porous permeable concrete was 30-35%.

[0070] 4) The ecological porous permeable concrete obtained in step 3) is evenly filled into a precast mold for curing and molding. The curing temperature is 18-22℃, the curing humidity is 93±2%, and the curing time is 28 days to obtain ecological porous permeable concrete.

[0071] The prepared ecological porous permeable concrete was a cubic specimen with a volume V1 = 150mm × 150mm × 150mm = 3375000mm. 3 .

[0072] The ecological porous permeable concrete prepared using the technical solution of this invention employs recycled aggregate and modified corn cob aggregate in the slope protection structure to improve the utilization rate of solid waste, reduce the consumption of natural resources, and improve the durability of the ecological slope protection material. Through properties such as high continuous porosity, high vegetation pore size, and low pH pore environment, the plant adaptability of the ecological slope protection is enhanced, thus overcoming the weaknesses of existing technologies in the research on the adaptability of slope protection plants and the utilization of corn cob building materials. This solves the problems of natural aggregate consumption and low vegetation coverage in river slope protection. The relevant performance test experiments are as follows:

[0073] 1. Vegetation pore size test:

[0074] According to the sand permeation method in "Vegetated Concrete" (JC / T 2557-2020), the pore size of the ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate prepared in Examples 1 to 4 of this invention was tested. The test results are detailed in Table 2.

[0075] 2. Pore pH value test:

[0076] The pore pH value of the ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate prepared in Examples 1-4 of this invention was tested using a pH meter (PHS-25) from Shanghai Leici Laboratory. Specimens cured for 28 days were immersed in a container of distilled water, with the water mass being three times the specimen mass. The water submerged the specimen surface by 2-4 mm, and the immersion time was 24 hours. After immersion, the pH value was measured using the laboratory pH meter. The test results are detailed in Table 2.

[0077] 3. Continuous porosity test:

[0078] According to the continuous porosity test method for permeable cement concrete in Appendix A of the "Technical Specification for Application of Recycled Aggregate Permeable Concrete" (CJJ / T 253-2016), the continuous porosity of the ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate prepared in Examples 1 to 4 of this invention was tested. The test results are shown in Table 2.

[0079] 4. 28-day compressive strength test:

[0080] In accordance with the requirements of the "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" (GB / T 50081-2019), the 28-day compressive strength of the ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate prepared in Examples 1 to 4 of this invention was tested. The test results are detailed in Table 2.

[0081] Table 2. Performance test results of the ecological porous permeable concrete prepared in Examples 1-4 of this invention.

[0082]

[0083] 5. Freeze resistance test:

[0084] According to the rapid freezing method in the "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete" (GB / T 50082-2009), the compressive strength loss and mass loss of the ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate prepared in Examples 1-4 of this invention were tested. After 24 days of standard curing, the specimens were immersed in distilled water at a temperature of 20±2℃ for 4 days. After immersion, the specimens were placed in a freeze-thaw chamber for freezing at an air temperature of -18℃ for 2 hours. Subsequently, water was injected to thaw the specimens at an air temperature of 20℃ for 2 hours. One cycle lasted 4 hours, and a total of 25 cycles were performed. The test results are shown in Table 3.

[0085] 6. Sulfate resistance test:

[0086] According to the "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete" (GB / T 50082-2009), the corrosion resistance coefficient and mass loss of the ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate prepared in Examples 1-4 of this invention were tested under the wet-dry cycle test under sulfate attack. After 26 days of standard curing, the specimens were dried in an oven at 80±5℃ for 48 days. After drying, the specimens were immersed in anhydrous sodium sulfate solution in a wet-dry cycle chamber for 15 hours. The anhydrous sodium sulfate solution was then drained, and the specimens were air-dried for 1 hour. The specimens were then heated to 80℃ for 6 hours and cooled to 25℃ for 2 hours. One cycle lasted 24 hours, and a total of 30 cycles were performed. The test results are detailed in Table 3.

[0087] Table 3. Results of frost resistance and sulfate attack resistance tests on the ecological porous permeable concrete prepared in Examples 1-4.

[0088]

[0089] Vegetation pore size is an indicator of the suitable proportion of pore size for plants, with 50-60% being ideal. Pores can be classified into connected pores, semi-connected pores, and closed pores based on their connectivity. Connected and semi-connected pores are collectively referred to as continuous pores. The proportion of continuous pore volume in the theoretical volume of concrete is called continuous porosity. Continuous porosity characterizes the proportion of pore volume that water can enter the specimen, with 25-30% being ideal. Pore pH value characterizes the degree of leaching of alkaline hydrates from the pores inside the specimen; the closer it is to 7, the better the porosity. Suitable environmental conditions for plant growth are required; compressive strength characterizes the material's resistance to maximum uniform plastic deformation; freeze-thaw cycle mass loss rate characterizes the material's failure behavior, and the closer it is to 0%, the better; freeze-thaw cycle compressive strength loss rate characterizes the degree of reduction in material strength under shrinkage-expansion fatigue, and the closer it is to 0%, the better; wet-dry cycle mass loss rate characterizes the material's failure or filling behavior, and the closer it is to 0%, the better; wet-dry cycle corrosion resistance coefficient characterizes the degree of increase or decrease in material strength, and the closer it is to 0%, the better.

Claims

1. A porous ecological material for slope protection with good toughness and durability, characterized in that: The ecological slope protection porous material is an ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate. Expressed as a mass percentage, the ecological porous permeable concrete consists of 45-67% recycled aggregate, 3-15% modified corn cob aggregate, 21-28% cement, and 9-12% water. The recycled aggregate is obtained by crushing waste concrete pavement, yielding recycled aggregate with two particle sizes: 4.75-9.5mm and 9.5-19mm. The modified corn cob aggregate is treated natural corn cobs with a diameter of 4.75-9.5mm and a compressive strength of 0.9MPa. The cement is P·O. 42.5 grade ordinary Portland cement; the treatment method for the modified corn cob aggregate is as follows: a) Place sodium silicate solution and cut natural corn cobs (4.75-9.5 mm) in a pressure impregnation tank, ensuring the natural corn cobs are completely immersed in the sodium silicate solution, then seal the tank; the initial modulus of the sodium silicate solution is 3.3, the water content is 64.16%, and the Baume degree is 38.5°Bé; b) After sealing, evacuate the air to -0.1 to -0.5 MPa and maintain this pressure for 10-15 minutes. c) Release the pressure to 0.5–2.0 MPa and maintain it for 20–30 min; d) After repeating step b 3–6 times, remove the corn cobs and clean them, then let them stand; e) Place the settled corn cobs in an oven at 120±5℃ for drying for 6–12 h; f) Remove the dried corn cobs and place them in an indoor environment at 20±2℃ for cooling for 3–6 h, resulting in modified corn cob aggregate with a diameter of 4.75–9.5 mm.

2. A method for preparing a porous ecological material for slope protection with good toughness and durability, characterized in that, The preparation method includes the following steps: 1) Weighing various raw materials according to the proportion of the ecological porous permeable concrete described in claim 1; 2) Pouring the weighed recycled aggregate, modified corn cob aggregate and part of water into a mixer in sequence for mixing; 3) Then adding the weighed cement and the remaining water and continuing to mix. After thorough mixing, ecological porous permeable concrete based on recycled aggregate and modified corn cob aggregate is obtained; 4) The ecological porous permeable concrete obtained in step 3) is uniformly filled into a precast mold for curing and molding to obtain an ecological slope protection porous ecological material with good toughness and durability.

3. The method for preparing the porous ecological slope protection material with good toughness and durability according to claim 2, characterized in that: When stirring as described in step 2), the stirring temperature is room temperature, the stirring speed is 50-60 r / min, the stirring time is 20-30 s, and the water accounts for 40-50% of the water mass.

4. The method for preparing the porous ecological slope protection material with good toughness and durability according to claim 2, characterized in that: During the mixing process described in step 3), the mixing temperature is room temperature, the mixing rate is 50-60 r / min, and the mixing time is 2-3 min; the porosity of the resulting ecological porous permeable concrete is 30-35%.

5. The method for preparing the porous ecological slope protection material with good toughness and durability according to claim 2, characterized in that: The curing temperature in step 4) is 18–22℃, the curing humidity is 93±2%, and the curing time is 28–56 days.

6. The method for preparing the porous ecological slope protection material with good toughness and durability according to claim 2, characterized in that: Step 4) The precast mold contains a cubic specimen with a side length of 150mm.

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