Porous vegetation concrete for slope ecological protection and preparation method thereof

Abstract

The application discloses a kind of porous vegetation concrete for slope ecological protection and preparation method thereof, a kind of porous vegetation concrete for slope ecological protection includes water, coarse aggregate, sulphoaluminate cement, basalt fiber, modified rice straw fiber, additive, water reducing agent, ecological modifier, wherein, additive includes pinecone powder and shell powder;The mass ratio of pinecone powder and shell powder is (10~12):(4~6);The preparation method of a kind of porous vegetation concrete for slope ecological protection, in to mix uniformly above-mentioned each raw material.The porous vegetation concrete for slope ecological protection of the application has good porosity, mechanical strength and durability.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and in particular to a porous vegetation concrete for ecological slope protection and its preparation method. Background Technology

[0002] Slope ecological restoration can be defined as "using a combination of living and non-living plant materials and civil engineering techniques to reduce slope instability and erosion." Currently, porous vegetation concrete ecological slope protection technology is widely used for the ecological restoration of various types of earth-rock slopes, hardened slopes, and rock slopes.

[0003] Porous vegetation concrete ecological slope protection technology refers to pouring porous vegetation concrete on a slope, then planting plants within the concrete pores. The plant roots penetrate the concrete and reach the slope surface, achieving the dual effect of slope reinforcement and vegetation restoration. The most significant feature of this technology is its ability to adapt to plant root growth, re-establishing a plant growth zone on the slope; hence, the material used in this technology is figuratively called porous vegetation concrete.

[0004] The technical challenge of porous vegetation concrete lies in ensuring both porosity and maintaining certain mechanical properties. The strength of porous ecological concrete primarily comes from the interlocking force between coarse aggregate particles and the bonding force of the cementitious material. Coarse aggregates are strong and difficult to break; current technologies generally increase the amount of cementitious material to improve the bond strength between coarse aggregate joints, thereby enhancing the compressive strength of porous vegetation concrete. However, increasing the amount of cementitious material means increasing the content of soluble alkali in the porous vegetation concrete, which can negatively impact plant growth. Therefore, designing a low-alkali, high-strength porous vegetation concrete is essential, and there is still room for improvement in the formulation of porous vegetation concrete. Summary of the Invention

[0005] To ensure that porous vegetation concrete possesses both sufficient porosity and mechanical strength, this application provides a porous vegetation concrete for slope ecological protection and its preparation method. The porous vegetation concrete provided by this application features low alkalinity and high strength. This application's research found that adding a certain proportion of basalt fiber and modified straw fiber to porous vegetation concrete can maintain good mechanical strength without affecting its porosity and significantly improve its durability.

[0006] Firstly, the porous vegetation concrete provided in this application adopts the following technical solution:

[0007] A porous vegetation concrete for ecological slope protection comprises the following components in parts by weight:

[0008] Coarse aggregate: 150-155 parts;

[0009] Sulfoaluminate cement: 50-55 parts;

[0010] Basalt fiber: 2-3 parts;

[0011] Modified rice straw fiber: 4-5 parts;

[0012] Additive: 4-5 parts;

[0013] Water-reducing agent: 0.3–0.5 parts;

[0014] Ecological conditioner: 4-5 parts;

[0015] Water: 19–21 parts;

[0016] The additives include pine cone powder and shell powder;

[0017] The mass ratio of pine cone powder to shell powder is (10-12):(4-6);

[0018] The method for preparing the modified rice straw fiber includes the following steps:

[0019] Step 1: Take rice straw, cut it, shred it, remove impurities, wash and soak it in water, dry it, and crush it into powder to obtain pretreated rice straw fiber;

[0020] Step 2: Under ventilation conditions at a temperature of 30-40℃, the pretreated rice straw fiber is soaked in a 1% sodium hydroxide solution for 12-15 hours, then placed in a 1% nano-SiO2 suspension, shaken for 20-25 minutes, and dried to obtain modified rice straw fiber.

[0021] In step two, the volume ratio of rice straw fiber to 1% sodium hydroxide solution is 1:(15-20).

[0022] The 1% nano-SiO2 suspension mentioned in step two is prepared by adding KH-550 silane coupling agent to 90% ethanol and stirring for 20-25 minutes to prepare a 5% mixed solution; then, nano-SiO2 is added to the mixed solution and shaken for 20-25 minutes to obtain a 1% nano-SiO2 suspension.

[0023] The preferred method, according to the above technical solution, is to soak rice straw fibers in a 1% sodium hydroxide solution for 12-15 hours to remove sugars and hemicellulose from the rice straw fibers. Then, by grafting SiO2, the mechanical properties and hydrophobic properties of the rice straw fibers are improved, and the interfacial bonding force between the rice straw fibers and sulfoaluminate cement is enhanced.

[0024] By mixing modified straw fiber and basalt fiber, the modified straw fiber adheres to the surface of the basalt fiber, which not only increases the surface roughness of the basalt fiber, thus improving its hydrophobicity, but also enhances the dispersibility of the basalt fiber in cement and the interfacial bonding force between the basalt fiber and cement. The modified straw fiber and basalt fiber interact in the slurry, synergistically promoting the bonding force between the sulfoaluminate cement and the aggregate. With a reduction in the amount of sulfoaluminate cement, the internal microstructure of porous vegetation concrete is improved, constructing a network microstructure within the porous vegetation concrete, slowing down the loss of cementitious solids in the porous vegetation concrete, and enhancing the durability and mechanical strength of the porous vegetation concrete.

[0025] Selecting pine cone powder and shell powder within a specific dosage range of (10-12): (4-6), pine cone powder can reduce the agglomeration between raw materials and increase the dispersibility of raw materials in porous vegetation concrete, while shell powder can improve the bonding force between aggregates. The two work synergistically to significantly improve the internal density of porous vegetation concrete and improve the adhesion of colloidal materials to aggregates. Based on the internal network microstructure constructed by modified straw fiber and basalt fiber, the bonding force between internal raw materials is further enhanced, thereby reducing the amount of sulfoaluminate cement used, while increasing the internal density of porous vegetation concrete and enhancing the durability and mechanical strength of porous vegetation concrete.

[0026] Preferably, the mass ratio of basalt fiber to modified straw fiber is (2-2.5):(4.5-5).

[0027] In the above technical solution, the internal network microstructure of the porous vegetation concrete prepared according to the above technical solution is more stable.

[0028] Preferably, the length of the basalt fiber is 7-8 mm.

[0029] In the above technical solution, basalt fibers of 7-8 mm are selected, which can better cooperate with modified straw fibers and disperse them in porous vegetation concrete, and fully mix with sulfoaluminate cement to construct an internal network microstructure.

[0030] Preferably, the preparation method of the ecological conditioner includes the following steps:

[0031] 1. Chop rice straw and mix it with water at a ratio of 1:(0.65-0.7), add Bacillus licheniformis and let it decompose for 15-20 days to obtain a pre-modifier;

[0032] 2. Mix the pre-modifier and acidic phosphogypsum in a ratio of (40-45):(55-60) to obtain the ecological modifier.

[0033] In the above technical solution, the mass ratio of Bacillus licheniformis to the main material is 1:5000.

[0034] A natural pre-modifier is prepared by composting rice straw powder using Bacillus licheniformis, which is more conducive to providing nutrients for plant growth. The rice straw fiber contained in the straw can further improve the bonding strength of porous vegetation concrete. The pre-modifier is mixed with acidic phosphogypsum. Acidic phosphogypsum is acidic, with a pH value of generally 2.5 to 4.5. Acidic phosphogypsum can not only provide nutrients for plant growth and improve the binding ability of ecological modifier with other raw materials of porous ecological concrete, but also continuously regulate the pH in the pores of porous vegetation concrete, avoiding the death of plants due to excessively high pH value of porous vegetation concrete.

[0035] The ecological conditioner prepared in this application is a viscous slurry. Without reducing the mechanical strength of porous concrete, it can be well compatible with other raw materials in porous vegetation concrete, maintain the pH value of porous vegetation concrete below 9, fill the defect that porous vegetation concrete cannot provide nutrients to vegetation, and its fertility is slowly released in the concrete, continuously supplying nutrients to promote the growth of plant organisms, and ensuring that plant organisms can successfully penetrate the porous vegetation concrete and take root in the soil under the concrete.

[0036] Preferably, the coarse aggregate has a particle size range of 20-25 mm.

[0037] By selecting specific dosage ranges and coarse aggregates within specific particle size ranges as described in this application, and combining them with pine cone powder and shell powder, the resulting porous vegetation concrete exhibits a more uniform pore distribution. This also enhances the interlocking relationship between the porous vegetation concrete aggregates in this application, improves the stability of the concrete skeleton constructed by the aggregates, makes the physical stacking of the porous vegetation concrete more robust, and increases the compressive strength of the porous vegetation concrete.

[0038] Preferably, the water-reducing agent is a naphthalene-based high-efficiency water-reducing agent.

[0039] In the above technical solution, the naphthalene-based high-efficiency water-reducing agent was purchased from Wanshan Group, specification FDN-C. When mixed into porous vegetation concrete, it can better disperse the raw materials in the concrete without changing the fluidity of the porous vegetation concrete, thus effectively improving the mechanical properties of the porous vegetation concrete.

[0040] Secondly, this application provides a method for preparing porous vegetation concrete for slope ecological protection, which adopts the following technical solution:

[0041] A method for preparing porous vegetation concrete for ecological slope protection includes the following steps:

[0042] 1) Take 10% to 12% of water from the formula, add basalt fiber and modified rice straw fiber, and stir to mix evenly to obtain a premix;

[0043] 2) Take the remaining water and coarse aggregate from the formula, mix them evenly, then add sulfoaluminate cement, the premix from step 1), fine aggregate, admixture, water-reducing agent, and ecological improver, and stir to make porous vegetation concrete.

[0044] Preferably, step 2) involves first mixing 50%–60% of the water, 50%–60% of the sulfoaluminate cement, the premix from step 1), and coarse aggregate in the formula to obtain a first mixture; then mixing the remaining water, the remaining sulfoaluminate cement, admixtures, water-reducing agents, and ecological conditioners in the formula to obtain a second mixture; finally, adding the second mixture to the first mixture and mixing thoroughly to obtain porous vegetation concrete.

[0045] In the above technical solution, the porous vegetation concrete prepared according to the above steps has uniform mixing of each raw material, better mutual cooperation among the raw materials, and plays a role. Moreover, the preparation method is economical and has the prospect of industrial production.

[0046] In summary, this application includes at least one of the following beneficial technical effects:

[0047] 1. Modified rice straw fiber and basalt fiber are mixed. The modified rice straw fiber adheres to the surface of the basalt fiber, which not only increases the surface roughness of the basalt fiber, thereby improving its hydrophobicity, but also improves the dispersibility of the basalt fiber in cement and enhances the interfacial bonding force between the basalt fiber and cement. The modified rice straw fiber and basalt fiber interact in the slurry, synergistically promoting the bonding force between the sulfoaluminate cement and the aggregate, improving the internal microstructure of porous vegetation concrete, constructing a network microstructure inside the porous vegetation concrete, slowing down the loss of solid substances with cementing effect in the porous vegetation concrete, and enhancing the durability and mechanical strength of the porous vegetation concrete.

[0048] 2. Pine cone powder can reduce the agglomeration between raw materials and increase the dispersibility of raw materials in porous vegetation concrete, while shell powder can improve the bonding force between aggregates. When the mass ratio of pine cone powder to shell powder is (10-12):(4-6), the two work synergistically to significantly improve the internal density of porous vegetation concrete and the adhesion of colloidal materials to aggregates. Based on the internal network microstructure constructed by modified straw fiber and basalt fiber, the bonding force between internal raw materials is further enhanced, thereby reducing the amount of sulfoaluminate cement used. At the same time, the internal density of porous vegetation concrete is increased, and the durability and mechanical strength of porous vegetation concrete are enhanced.

[0049] 3. This application utilizes Bacillus licheniformis to decompose rice straw powder, preparing a natural pre-modifier that is more conducive to providing nutrients for plant growth. The rice straw fiber contained in the rice straw can further improve the bonding strength of porous vegetation concrete. When the pre-modifier is mixed with acidic phosphogypsum, the acidic phosphogypsum not only provides nutrients for plant growth and improves the bonding ability of the ecological modifier with the other raw materials of porous ecological concrete, but also continuously regulates the pH in the pores of porous vegetation concrete, preventing the plant from dying due to excessively high pH value of porous vegetation concrete.

[0050] 4. Based on the specific dosage range of this application and selecting coarse aggregate with a particle size of 20-25mm, it is combined with pine cone powder and shell powder to obtain porous vegetation concrete with more uniform pore distribution. It also enhances the interlocking between the porous vegetation concrete aggregates in this application, improves the stability of the concrete skeleton built by the aggregates, makes the physical stacking of porous vegetation concrete more solid, and improves the compressive strength of porous vegetation concrete. Detailed Implementation

[0051] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0052] Preparation Example 1

[0053] A modified rice straw fiber, the raw materials of which include rice straw, 1% sodium hydroxide solution, KH-550 silane coupling agent, and nano-SiO2.

[0054] The preparation of modified rice straw fiber includes the following steps:

[0055] Step 1: Take rice straw, cut it, shred it, remove impurities, wash and soak it in water, dry it, and crush it into powder to obtain pretreated rice straw fiber;

[0056] Step 2: Under ventilated conditions at 30℃, the pretreated rice straw fiber is soaked in a 1% sodium hydroxide solution for 15 hours, then placed in a 1% nano-SiO2 suspension, ultrasonically vibrated for 20 minutes, and dried to obtain modified rice straw fiber.

[0057] In step two, the volume ratio of rice straw fiber to 1% sodium hydroxide solution is 1:15.

[0058] In step two, the 1% nano-SiO2 suspension is prepared by adding KH-550 silane coupling agent to 90% ethanol and stirring for 20 minutes to prepare a 5% mixed solution; then, nano-SiO2 is added to the mixed solution and ultrasonically vibrated for 20 minutes to obtain a 1% nano-SiO2 suspension.

[0059] Preparation Example 2

[0060] A modified rice straw fiber, differing from preparation example 1 in that...

[0061] The preparation of modified rice straw fiber includes the following steps:

[0062] Step 1: Take rice straw, cut it, shred it, remove impurities, wash and soak it in water, dry it, and crush it into powder to obtain pretreated rice straw fiber;

[0063] Step 2: Under ventilation conditions at 40℃, the pretreated rice straw fiber is soaked in a 1% sodium hydroxide solution for 12 hours, then placed in a 1% nano-SiO2 suspension, ultrasonically vibrated for 25 minutes, and dried to obtain modified rice straw fiber.

[0064] In step two, the volume ratio of rice straw fiber to 1% sodium hydroxide solution is 1:20.

[0065] In step two, the 1% nano-SiO2 suspension is prepared by adding KH-550 silane coupling agent to 90% ethanol and stirring for 25 minutes to prepare a 5% mixed solution; then, nano-SiO2 is added to the mixed solution and ultrasonically vibrated for 25 minutes to obtain a 1% nano-SiO2 suspension.

[0066] Preparation Example 3

[0067] An ecological conditioner, the raw materials of which include water, rice straw, Bacillus licheniformis, and acidic phosphogypsum.

[0068] The preparation of the ecological conditioner includes the following steps:

[0069] Step (1): Chop the rice straw and mix it with water at a ratio of 1:0.65. Add Bacillus licheniformis and let it decompose for 15 days to obtain a pre-modifier.

[0070] Step (2): Mix the pre-modifier and acidic phosphogypsum in a ratio of 40:55 to obtain the ecological modifier.

[0071] Among them, Bacillus licheniformis was purchased from Weifang Yihao Biotechnology Co., Ltd., and its main components are live Bacillus licheniformis and its metabolites. Fertilizer registration number: Microbial Fertilizer (2018) Approval No. (2791).

[0072] Preparation Example 4

[0073] An ecological conditioner, which differs from preparation example 3 in that...

[0074] The preparation of the ecological conditioner includes the following steps:

[0075] Step (1): Chop the rice straw and mix it with water at a ratio of 1:0.7, add Bacillus licheniformis and let it decompose for 20 days to obtain a pre-modifier;

[0076] Step (2): Mix the pre-modifier and acidic phosphogypsum in a ratio of 45:60 to obtain the ecological modifier.

[0077] Preparation Example 5

[0078] An ecological conditioner, which differs from preparation example 3 in that...

[0079] The preparation of the ecological conditioner includes the following steps:

[0080] Step (1): Chop the rice straw and mix it with water at a ratio of 1:0.65. Add Bacillus licheniformis and let it decompose for 15 days to obtain an ecological improver.

[0081] Preparation Example 6

[0082] An ecological conditioner, which differs from preparation example 3 in that...

[0083] The preparation of the ecological conditioner includes the following steps:

[0084] Step (1): Chop the rice straw and mix it with water at a ratio of 1:0.65. Add Bacillus licheniformis and let it decompose for 15 days to obtain a pre-modifier.

[0085] Step (2): Mix the pre-modifier and natural gypsum in a ratio of 40:55 to obtain the ecological modifier.

[0086] Example 1

[0087] A porous vegetation concrete comprises 19 kg of water, 150 kg of coarse aggregate, 50 kg of sulfoaluminate cement, 2 kg of basalt fiber, 4 kg of modified straw fiber, 4 kg of admixture, 0.3 kg of water-reducing agent, and 4 kg of ecological improver.

[0088] The modified fiber straw was prepared in Example 1.

[0089] The ecological improver was derived from Preparation Example 3.

[0090] The basalt fiber is 7 mm in length.

[0091] The coarse aggregate is a continuous grade of crushed stone with a particle size range of 19 to 26 mm.

[0092] The additive is a mixture of pine cone powder and shell powder in a ratio of 10:4.

[0093] Among them, pine cone powder is made by directly crushing pine cones into powder, and shell powder is made by directly crushing shells into powder.

[0094] The water-reducing agent is a naphthalene-based high-efficiency water-reducing agent, purchased from Wanshan Group, specification FDN-C.

[0095] The preparation method of porous vegetation concrete includes the following steps:

[0096] Step 1): Take 12% of the water in the formula, add basalt fiber and modified rice straw fiber, and stir to mix evenly to obtain a premix.

[0097] Step 2): Take the remaining water and coarse aggregate from the formula, mix them evenly, then add sulfoaluminate cement, the premix from Step 1), admixtures, water-reducing agents, and ecological improvers, and stir until well mixed to form porous vegetation concrete.

[0098] Example 2

[0099] A porous vegetation concrete, unlike Example 1, includes 21 kg of water, 155 kg of coarse aggregate, 55 kg of sulfoaluminate cement, 3 kg of basalt fiber, 5 kg of modified straw fiber, 5 kg of admixture, 0.5 kg of water-reducing agent, and 5 kg of ecological improver.

[0100] The modified fiber straw was prepared in Example 2.

[0101] The ecological improver was derived from preparation example 4.

[0102] The basalt fiber is 8 mm in length.

[0103] The coarse aggregate is a continuous grade of crushed stone with a particle size range of 16 to 22 mm.

[0104] The additive is a mixture of pine cone powder and shell powder in a ratio of 12:6.

[0105] The preparation method of porous vegetation concrete includes the following steps:

[0106] Step 1): Take 10% of the water by mass from the formula, add basalt fiber and modified rice straw fiber, and stir to mix evenly to obtain a premix;

[0107] Step 2): Take the remaining water and coarse aggregate from the formula, mix them evenly, then add sulfoaluminate cement, the premix from Step 1), admixtures, water-reducing agents, and ecological improvers, and stir until well mixed to form porous vegetation concrete.

[0108] Example 3

[0109] A porous vegetation concrete, unlike Example 1, includes 19 kg of water, 150 kg of coarse aggregate, 50 kg of sulfoaluminate cement, 2 kg of basalt fiber, 4.5 kg of modified straw fiber, 4 kg of admixture, 0.3 kg of water-reducing agent, and 4 kg of ecological improver.

[0110] Example 4

[0111] A porous vegetation concrete, unlike Example 2, includes 21 kg of water, 155 kg of coarse aggregate, 55 kg of sulfoaluminate cement, 2.5 kg of basalt fiber, 5 kg of modified straw fiber, 5 kg of admixture, 0.5 kg of water-reducing agent, and 5 kg of ecological improver.

[0112] Example 5

[0113] A porous vegetation concrete, unlike Example 2, includes 20 kg of water, 153 kg of coarse aggregate, 52 kg of sulfoaluminate cement, 2.2 kg of basalt fiber, 4.6 kg of modified straw fiber, 4.5 kg of admixture, 0.4 kg of water-reducing agent, and 4.5 kg of ecological improver.

[0114] The additive is a mixture of pine cone powder and shell powder in a ratio of 11:5.

[0115] The preparation method of porous vegetation concrete includes the following steps:

[0116] Step 1): Take 10% of the water by mass from the formula, add basalt fiber and modified rice straw fiber, and stir to mix evenly to obtain a premix;

[0117] Step 2): First, mix 60% of the water, 50% of the sulfoaluminate cement, the premix from Step 1), and coarse aggregate in the formula to obtain the first mixture; then mix the remaining water, the remaining sulfoaluminate cement, admixtures, water-reducing agents, and ecological conditioners in the formula to obtain the second mixture; add the second mixture to the first mixture and mix well to obtain porous vegetation concrete.

[0118] Example 6

[0119] A porous vegetation concrete, unlike Example 5, uses coarse aggregates that are continuous grade crushed stone with a particle size range of 20 to 25 mm.

[0120] Example 7

[0121] A porous vegetation concrete, unlike Example 2, uses an ecological amendment derived from Preparation Example 5.

[0122] Example 8

[0123] A porous vegetation concrete, unlike Example 2, uses an ecological modifier derived from Preparation Example 6.

[0124] Comparative Example 1

[0125] A porous vegetation concrete, which differs from Example 2 in that basalt fibers are replaced in equal amounts with modified rice straw long fibers.

[0126] The method for preparing modified rice straw long fibers differs from that in Preparation Example 2.

[0127] Step 1: Take rice straw, cut it, shred it, remove impurities, wash and soak it in water, and dry it to obtain pretreated rice straw fiber;

[0128] Step 2: Under ventilated conditions at 40℃, the pretreated rice straw fibers are soaked in a 1% sodium hydroxide solution for 12 hours, then placed in a 1% nano-SiO2 suspension, ultrasonically vibrated for 25 minutes, dried, and cut into 8mm lengths to obtain modified rice straw long fibers.

[0129] Comparative Example 2

[0130] A porous vegetation concrete, which differs from Example 2 in that modified rice straw fiber is replaced with an equal amount of rice straw fiber.

[0131] The preparation method of rice straw fiber is as follows:

[0132] Step 1: Take rice straw, cut it, shred it, remove impurities, wash and soak it in water, and dry it to obtain pretreated rice straw fiber;

[0133] Step 2: Under ventilated conditions at 40℃, the pretreated rice straw fiber is soaked in a 1% sodium hydroxide solution for 12 hours to obtain rice straw fiber.

[0134] Comparative Example 3

[0135] A porous vegetation concrete, unlike Example 2, does not contain pine cone powder.

[0136] Comparative Example 4

[0137] A porous vegetation concrete, unlike Example 2, does not contain shell powder.

[0138] Comparative Example 5

[0139] A porous vegetation concrete, unlike Example 2, uses an admixture made of pine cone powder and shell powder in a 9:3 ratio.

[0140] Comparative Example 6

[0141] A porous vegetation concrete, unlike Example 2, uses an admixture made of pine cone powder and shell powder in a 13:7 ratio.

[0142] test

[0143] I. Compressive strength test:

[0144] Referring to the "Standard for Test Methods of Mechanical Properties of Ordinary Concrete", the testing instrument was a TYE-2000E compression testing machine. Porous vegetation concrete samples of the above embodiments and comparative examples were prepared into 150mm diameter sections. 3 The standard specimens were subjected to uniaxial compressive strength tests on cubic specimens, and the compressive strength was recorded. The test results are shown in Table 1.

[0145] II. Effective Porosity Test

[0146] Referring to the US "Standard Method for Testing Effective Porosity of Compacted Asphalt Specimens", the test principle is the drainage method, using mass measurement. The specific method is as follows:

[0147] 1. Prepare the sample to be tested into a D*H: 100*100mm 2 The specimens were then air-dried naturally.

[0148] 2. Vacuum-sealed packaging of test specimens;

[0149] 3. Weigh the specimen and measure its mass m1 in air;

[0150] 4. Use a hydrostatic balance to weigh the mass m2 of the sealed specimen in water;

[0151] (5) Cut open the sealed bag in the water and weigh the mass m3 at this time.

[0152] The effective porosity is calculated as follows: P = [(m3-m2) / (m1-m2)] * 100%. The effective porosity is recorded, and the test results are shown in Table 1.

[0153] III. Anti-carbonization performance test

[0154] The experiment was conducted in accordance with GB / T50082-2009 "Test Methods for Long-Term Performance and Durability of Ordinary Concrete". Two groups of 150mm porous vegetation concrete were prepared from the above-mentioned examples and comparative examples. 3Two groups of specimens were cured under standard conditions for 26 days, then removed and dried at 60℃ for 2 days. One group of specimens served as the rapid carbonization group, placed in a carbonization chamber with a CO2 concentration of (20±3)%, relative humidity of (70±5)%, and temperature of (20±5)℃ for 28 days. The other group served as the control group, continuing standard curing for another 28 days. After 28 days, both groups of specimens were removed and their mass and compressive strength were tested. The rate of change in compressive strength and the rate of change in mass were calculated. The rate of change in compressive strength (%) = [(compressive strength of control group - compressive strength of rapid carbonization group) / compressive strength of control group] * 100%, and the rate of change in mass (%) = [(mass of control group - mass of rapid carbonization group) / mass of control group] * 100%. The test results are shown in Table 1.

[0155] IV. Soil Alkalinity Testing: Porous vegetation concrete samples from the above embodiments and comparative examples were prepared into 150mm thick layers. 3 The standard specimens were filled with soil slurry (a mixture of water and soil at a weight ratio of 3:5) in their pores. After being left under natural conditions for 90 days, the pH value of the soil in the pores of the porous vegetation concrete was measured. During the measurement, soil from inside the pores was taken and mixed with water at a ratio of 1:2.5. The mixture was thoroughly stirred and the pH value of the mixture was measured using a PHS-3E pH meter. The pH value was recorded. The test results are shown in Table 1.

[0156] Table 1:

[0157]

[0158]

[0159] As can be seen from Table 1, the porous vegetation concrete of Examples 1-8 has good mechanical strength and durability, as well as higher effective porosity and lower pH value.

[0160] The difference between Example 2 and Comparative Examples 1-2 is that Comparative Example 1 uses modified rice straw long fibers instead of basalt fibers, while Comparative Example 2 uses ordinary rice straw fibers instead of modified rice straw fibers. The compressive strength, durability, and effective porosity of Example 2 are all superior to those of Comparative Examples 1-2 to a certain extent, and the pH value of Example 2 is lower than that of Comparative Examples 1-2. From this analysis, it can be concluded that only when modified rice straw fibers and basalt fibers are mixed can the modified rice straw fibers and basalt fibers interact in the slurry, synergistically promoting the bonding force between sulfoaluminate cement and aggregates, improving the internal microstructure of porous vegetation concrete, constructing a network microstructure inside the porous vegetation concrete, slowing down the loss of solid substances with cementing effect in the porous vegetation concrete, and enhancing the durability and mechanical strength of the porous vegetation concrete.

[0161] The difference between Examples 2 and 4, and Examples 1 and 3, is that the mass ratio of basalt fiber to modified straw fiber in Examples 3-4 is (2-2.5):(4.5-5). The compressive strength, durability, and effective porosity of Examples 3-4 are all superior to those of Examples 1-2 to a certain extent. Based on this analysis, it can be concluded that when basalt fiber and modified straw fiber are mixed in a mass ratio of (2-2.5):(4.5-5), the internal network microstructure of porous vegetation concrete is more stable.

[0162] The difference between Example 2 and Comparative Examples 3-4 is that Comparative Examples 3-4 use pine cone powder to replace shell powder in equal amounts, and shell powder to replace pine cone powder in equal amounts, respectively. The compressive strength, durability, and effective porosity of Example 2 are all superior to those of Comparative Examples 3-4 to a certain extent, and the pH value of Example 2 is lower than that of Comparative Examples 3-4. From this analysis, it can be concluded that pine cone powder and shell powder are indispensable in this application. Only when pine cone powder and shell powder can work together can the adhesion between internal raw materials be further enhanced on the basis of the internal network microstructure constructed by modified straw fiber and basalt fiber, thereby reducing the amount of sulfoaluminate cement used, while increasing the internal density of porous vegetation concrete, and enhancing the durability and mechanical strength of porous vegetation concrete.

[0163] The difference between Example 2 and Comparative Examples 5-6 is that the mass ratio of pine cone powder to shell powder in Comparative Examples 5-6 is not between (10-12):(4-6). The compressive strength, durability, and effective porosity of Example 2 are all superior to those of Comparative Examples 5-6 to a certain extent. The pH value of Example 2 is lower than that of Comparative Examples 5-6. Therefore, it can be concluded that only when the mass ratio of pine cone powder to shell powder is (10-12):(4-6) can the two work synergistically to significantly improve the internal density of porous vegetation concrete, improve the adhesion of colloidal materials to aggregates, increase the internal density of porous vegetation concrete, and enhance the durability and mechanical strength of porous vegetation concrete.

[0164] The difference between Example 2 and Examples 7-8 is that Example 7 did not use phosphogypsum, while Example 8 used natural gypsum instead of phosphogypsum. The compressive strength, durability, and effective porosity of Example 2 are all superior to those of Examples 7-8 to a certain extent, and the pH value of Example 2 is lower than that of Examples 7-8. Therefore, it can be concluded that the ecological conditioner prepared in this application can be well compatible with other raw materials in porous vegetation concrete without reducing the mechanical strength of porous concrete, and can maintain the pH value of porous vegetation concrete below 9. This fills the gap in the fact that porous vegetation concrete cannot provide nutrients to vegetation. Its fertility is slowly released in the concrete, continuously supplying nutrients to promote the growth of plant organisms and ensuring that plant organisms can successfully penetrate the porous vegetation concrete and take root in the soil under the concrete.

[0165] The difference between Example 2 and Example 6 is that Example 6 uses coarse aggregate with a particle size of 20-25mm. The compressive strength, durability, and effective porosity of Example 6 are all superior to those of Example 2 to a certain extent. Therefore, it can be concluded that selecting coarse aggregate with a particle size of 20-25mm, combined with pine cone powder and shell powder, results in a more uniform pore distribution in the porous vegetation concrete. It also enhances the interlocking relationship between the aggregates in the porous vegetation concrete of this application, improves the stability of the concrete skeleton built by the aggregates, makes the physical stacking of the porous vegetation concrete more solid, and improves the compressive strength of the porous vegetation concrete.

[0166] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A porous vegetation concrete for ecological slope protection, characterized in that, The components include the following parts by mass: Coarse aggregate: 150-155 parts; Sulfoaluminate cement: 50-55 parts; Basalt fiber: 2-3 parts; Modified rice straw fiber: 4-5 parts; Additive: 4-5 parts; Water-reducing agent: 0.3~0.5 parts; Ecological conditioner: 4-5 parts; Water: 19-21 parts; The additives include pine cone powder and shell powder; The mass ratio of pine cone powder to shell powder is (10~12):(4~6); The method for preparing the modified rice straw fiber includes the following steps: Step 1: Take rice straw, cut it, shred it, remove impurities, wash and soak it in water, dry it, and crush it into powder to obtain pretreated rice straw fiber; Step 2: Under ventilation conditions at a temperature of 30~40℃, soak the pretreated rice straw fiber in a 1% sodium hydroxide solution for 12~15h, then put it into a 1% nano SiO2 suspension, shake for 20~25min, and dry to obtain modified rice straw fiber. In step two, the volume ratio of rice straw fiber to 1% sodium hydroxide solution is 1:(15~20). The 1% nano-SiO2 suspension mentioned in step two is prepared by adding KH-550 silane coupling agent to 90% ethanol and stirring for 20-25 minutes to prepare a 5% mixed solution; then, nano-SiO2 is added to the mixed solution and shaken for 20-25 minutes to obtain a 1% nano-SiO2 suspension. The preparation method of the ecological conditioner includes the following steps: After chopping rice straw, it is mixed with water at a ratio of 1:(0.65~0.7) and Bacillus licheniformis is added. The mixture is allowed to decompose for 15~20 days to obtain a pre-modifier. The pre-modifier and acidic phosphogypsum are mixed in a ratio of (40~45):(55~60) to obtain the ecological modifier.

2. The porous vegetation concrete for ecological slope protection according to claim 1, characterized in that, The mass ratio of basalt fiber to modified straw fiber is (2~2.5):(4.5~5).

3. The porous vegetation concrete for ecological slope protection according to claim 1, characterized in that, The basalt fibers are 7-8 mm in length.

4. The porous vegetation concrete for ecological slope protection according to claim 1, characterized in that, The coarse aggregate has a particle size range of 20~25mm.

5. A porous vegetation concrete for ecological slope protection according to claim 1, characterized in that, The water-reducing agent is a naphthalene-based high-efficiency water-reducing agent.

6. A method for preparing porous vegetation concrete for slope ecological protection as described in any one of claims 1-5, characterized in that, Includes the following steps: 1) Take 10%~12% of water from the formula, add basalt fiber and modified rice straw fiber, and stir to mix evenly to obtain a premix; 2) Take the remaining water and coarse aggregate from the formula, mix them evenly, then add sulfoaluminate cement, the premix from step 1), admixtures, water-reducing agents, and ecological improvers, and stir until well mixed to form porous vegetation concrete.

7. A method for preparing porous vegetation concrete for ecological slope protection according to claim 6, characterized in that, Step 2) involves first mixing 50% to 60% of the water, 50% to 60% of the sulfoaluminate cement, the premix from step 1), and coarse aggregate in the formula to obtain a first mixture; then mixing the remaining water, the remaining sulfoaluminate cement, admixtures, water-reducing agents, and ecological conditioners in the formula to obtain a second mixture; finally, adding the second mixture to the first mixture and mixing thoroughly to obtain porous vegetation concrete.

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