A kind of slope protection ecological concrete and its preparation process

Abstract

The invention discloses a slope protection ecological concrete, which relates to the technical field of ecological concrete. The concrete comprises the following raw materials in parts by weight: 1000-1080 parts of cement, 3650-3850 parts of aggregate, 310-350 parts of water, 140-160 parts of mineral admixture, 8-9.6 parts of polyacrylate, 40-45 parts of hydroxypropyl methylcellulose, 12-12.8 parts of polycarboxylate water reducer, 12-14 parts of composite fiber, and 60-68 parts of wood activated carbon. The prepared slope protection ecological concrete not only has excellent vegetative properties and water purification properties, but also has high strength and good durability.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological concrete, in particular to a slope protection ecological concrete and a preparation process thereof. Background Art

[0002] With the rapid development of my country's economy and the massive construction of infrastructure, whether it's mining, river excavation, road construction, or urban development, a large number of slopes are generated. Modern slope protection projects emphasize the harmonious coexistence of man and nature, ecological protection, and environmental friendliness. How to manage these exposed slopes has become a new challenge for engineers. Ordinary cast-in-place concrete slopes have the characteristics of good integrity, dense structure, simple construction, and high strength, but they ignore the ecological and landscape effects of the project. Their dense structure is not conducive to the circulation of surface water and groundwater, and vegetation cannot grow. The heat exchange between the upper and lower slopes is difficult, exacerbating the urban heat island effect.

[0003] Currently, common ecological concrete is made from materials such as cement, aggregate, water, and admixtures. Aggregates are usually graded in a single or discontinuous manner, forming a skeleton structure with interconnected pores. This increases the void ratio of the concrete, thereby enhancing its vegetative and water-purifying properties. However, ordinary coarse aggregates have few internal pores, poor water storage capacity, and a high-alkaline internal environment that is not suitable for vegetation growth. Volcanic rock is a porous, environmentally friendly stone material with high strength, light weight, and numerous interconnected pores. It has certain characteristics such as absorbing water and releasing oxygen, regulating air temperature, increasing green space, restoring ecology, improving landscapes, and beautifying the environment. It is suitable for plant growth, and plant roots can take root inside it, extending vertically and horizontally to create a special concrete "reinforcement" effect, which helps stabilize slopes. At the same time, due to its porous honeycomb structure, it has a better water storage capacity than ordinary stone. However, the main problems with using volcanic rocks to prepare ecological concrete are: first, the sole use of volcanic rocks as aggregates has limited phytoremediation and water purification effects; second, the strength of ecological concrete depends on the strength of the cement paste bonding points between the aggregates. Therefore, the greater the porosity of the concrete, the less strength and durability it has. On the banks of rivers, lakes, reservoirs, etc. that are often eroded by water and have slightly steeper slopes, the slope protection layer is prone to sliding or falling off. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to address the shortcomings of the existing technology and provide a slope protection ecological concrete, which uses volcanic rock and porous expanded clay as aggregates and optimizes the bonding strength between the aggregates and the binder. The prepared slope protection ecological concrete not only has excellent vegetation and water purification properties, but also has high strength and good durability.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A slope protection ecological concrete comprises the following raw materials in parts by weight: 1000-1080 parts of cement, 3650-3850 parts of aggregate, 310-350 parts of water, 140-160 parts of mineral admixture, 8-9.6 parts of polyacrylate, 40-45 parts of hydroxypropyl methylcellulose, 12-12.8 parts of polycarboxylate water reducer, 12-14 parts of composite fiber, and 60-68 parts of wood activated carbon.

[0007] Furthermore, the mineral admixture is a mixture of slag powder, fly ash, nano-silicon dioxide and metakaolin in a weight ratio of 2-3:2:0.5:3.

[0008] Furthermore, the composite fiber is a mixture of zinc phosphate modified steel fiber, silane coupling agent modified basalt fiber, and polypropylene fiber in a mass ratio of 4-5:3:7.

[0009] Furthermore, the zinc phosphate modified steel fiber is prepared by the following steps:

[0010] (1) Immerse the steel fiber in a 0.1M NaOH solution and heat it in a water bath at 55°C for 1-2 minutes, then rinse it with distilled water; then immerse it in a 0.1M HCl solution and heat it in a water bath at 60°C for 3-5 minutes, then rinse it with distilled water;

[0011] (2) Immerse the pickled steel fiber in a 0.01M H2O2 solution and stir for 2-3 minutes for activation, rinse with distilled water, and dry at 150°C;

[0012] (3) Immerse the activated steel fiber in a phosphating bath at 80°C for 50-60 minutes, rinse with distilled water, and then place it in an environment at 150°C for 20 minutes. After it is dried and solidified, zinc phosphate-modified steel fiber is obtained; 1L of the phosphating bath is composed of 0.6gZn(NO3)2, 5gZnO, 18-22ml85%H3PO4, 0.2gCaO and distilled water.

[0013] Furthermore, the silane coupling agent modified basalt fiber is prepared by the following steps:

[0014] (1) Place basalt fiber in 0.1-0.15wt% sodium polyacrylate solution, stir evenly, disperse by ultrasonic for 5-8 minutes, rinse with distilled water, and heat treat at 550℃ for 40-45 minutes;

[0015] (2) Activate the heat-treated basalt fiber in concentrated hydrochloric acid for 60 minutes, rinse with distilled water, and dry at an ambient temperature of 150°C for 15-20 minutes;

[0016] (3) Immersing the activated basalt fiber in an aminosilane coupling agent solution for 8-12 minutes, filtering and draining the solution, and then drying and curing the solution at an ambient temperature of 120°C for 40-60 minutes to obtain a silane coupling agent-modified basalt fiber;

[0017] The aminosilane coupling agent solution is prepared by mixing γ-aminopropyltriethoxysilane, deionized water and ethanol in a weight ratio of 1:2-4:8-10.

[0018] Furthermore, the wood activated carbon is made from eucalyptus chips, which are carbonized at 400°C for 60 minutes under N2 gas flow, and then activated with CO2 at 900°C for 90 minutes. After grinding, particles with a size of ≤30 μm are screened for use.

[0019] Furthermore, the aggregate is a mixture of volcanic rock and porous ceramsite in a weight ratio of 2:0.5-1.

[0020] Furthermore, the porous ceramsite has a two-layer structure of an inner core layer and a coating layer, and is prepared by the following steps:

[0021] (1) The raw materials used for the inner core layer and the coating layer are the same, including the following components in parts by weight: 35-40 parts of red mud, 30-35 parts of fly ash, 10-12 parts of glass fiber, 4-5 parts of coal powder, 2-3 parts of calcium carbonate whiskers, 4-6 parts of activated alumina and 2-3 parts of dextrin; the particle size of the coal powder in the raw material of the inner core layer is 70-150 μm, and the particle size of the coal powder in the raw material of the coating layer is 50-70 μm;

[0022] (2) After the raw materials of the inner core layer are mixed evenly, water is added to granulate to prepare an inner core with a particle size of 15 mm, and then the raw materials of the coating layer are added to continue granulation to prepare raw material balls with a particle size of 20 mm, and then dried;

[0023] (3) Firing at 1200℃ for 15-20min and cooling in the furnace;

[0024] (4) The fired product is immersed in a 1.5-2wt% NaOH solution, kept at 80°C for 1-1.5 hours, and then washed and dried to obtain the product.

[0025] Furthermore, the volcanic rock has a particle size of 16-25 mm, accounting for 1 / 2, and a bulk density of 1410 kg / m 3 The particle size is 25-35mm, accounting for 1 / 2, and the bulk density is 1346kg / m 3 .

[0026] A preparation process of slope protection ecological concrete includes the following steps:

[0027] (1) Soak the aggregate for 24 hours and let it air dry naturally;

[0028] (2) The mineral admixture, 1 / 2 of the water, and the aggregate were mixed and stirred for 3 minutes to obtain premix A; the cement and the composite fiber were mixed and stirred for 2 minutes, and the composite fiber was added three times, with the first stirring time of 0.5 minutes, the second stirring time of 0.5 minutes, and the third stirring time of 1 minute to obtain premix B; the premix A and premix B were mixed and stirred for 1 minute to obtain a mixed slurry C;

[0029] (3) Add polycarboxylate water reducer, polyacrylate and hydroxypropyl methylcellulose to the mixed slurry C, and add the remaining 1 / 2 of water and wood activated carbon, mix and stir for 3 minutes; after stirring evenly, use a tamping rod to tamp 25-35 times from the periphery to the middle layer by layer for 3 times, and press into shape at 0.3-0.5MPa, and send it to a standard curing room for curing for 28 days;

[0030] (4) The cured concrete is sprayed 3-5 times with a mixed acid consisting of 2-3 wt% phosphoric acid and 2-3 wt% oxalic acid in a ratio of 1:1 at intervals of 24 hours to obtain slope protection ecological concrete.

[0031] The beneficial effects of the present invention are:

[0032] 1. The present application discloses a slope protection ecological concrete, which uses volcanic rock and porous expanded clay as aggregates, which can increase the vegetation and water purification properties of the concrete. At the same time, in order to ensure the strength, mineral admixtures, polyacrylates and composite fibers are added. The finally prepared ecological concrete has excellent strength and durability, good porosity, water absorption rate and water storage capacity, and can effectively improve the vegetation and water purification properties of the ecological concrete while also having durability.

[0033] 2. The volcanic rock in the aggregate used in this application has the characteristics of high strength, large porosity, interconnected pores, water retention and air permeability, which is suitable for plant growth; and in order to further increase the water retention and water purification performance of the aggregate, it is also compounded with porous ceramsite. The porous ceramsite is designed as a two-layer structure. The matrix is ​​mainly prepared from red mud, fly ash, coal powder, glass fiber, calcium carbonate whiskers, activated alumina and dextrin. The particle size of the coating layer coal powder is smaller than that of the inner layer, which can increase the moisture retention time, increase the plant growth and water purification performance.

[0034] The red mud and fly ash used in the porous ceramsite raw materials are low-cost. The added glass fiber and activated alumina are evenly distributed throughout the matrix, filling voids, promoting sintering, and increasing matrix density. Calcium carbonate whiskers, coal powder, and dextrin are also added. Dextrin initially acts as a binder, increasing the cohesive properties of the raw material. During the heating phase, it slowly carbonizes, creating uniform micropores in the matrix. The coal powder gradually decreases in particle size from the inner to the outer layer, forming a gradually decreasing pore structure after high-temperature roasting. A small amount of calcium carbonate whiskers synergizes with the coal powder and dextrin to form small, evenly distributed interconnected voids in the porous ceramsite, helping to increase water retention. These ingredients decompose at different temperatures, ensuring a uniform and slow pore formation rate, thus ensuring matrix strength.

[0035] After firing, the porous expanded clay is hydrothermally kept warm in alkaline solution, so that the silicon and aluminum on the surface and in the gaps of the porous expanded clay are dissolved, and then undergo condensation reaction, nucleation and growth under alkaline conditions, making the surface and gaps of the porous expanded clay rougher and having a certain strength, which is conducive to the attachment of microorganisms, forming a microorganism-plant-soil ecological system, promoting the growth of plant roots and stems, and increasing water purification performance.

[0036] 3. The interface transition zone between aggregate and binder in eco-concrete is the weakest point. The added mineral admixtures include slag powder, fly ash, nano-silica, and metakaolin of varying particle sizes. On the one hand, these admixtures repair surface cracks in the volcanic aggregate, increase the number of contact points between the aggregates, and thus broaden the interface area. On the other hand, they fill the coarse pores of varying sizes in the interface transition zone, creating a dense micro-aggregate filling effect that achieves a densely packed state and enhances the strength of the structural network in the interface transition zone. Furthermore, the crystallization and crystallization stress generated by the secondary hydration reaction between the active ingredients of the admixtures and the cement hydration products further densify the interface transition zone, reducing microscopic defects in the transition zone, enhancing the structural density of the eco-concrete, and improving its durability and compressive strength.

[0037] Polyacrylate adheres to the surfaces of cement colloid and volcanic rock aggregate particles, forming a tough, dense film that improves the mortar's compactness and further reduces and refines cracks. Hydroxypropyl methylcellulose, a surfactant, readily forms hydrogen bonds with water molecules, providing hygroscopic, dispersing, and thickening properties. This improves water retention and enhances the fluidity of the concrete paste, facilitating construction and improving the uniformity and stability of the concrete.

[0038] 4. In order to further increase the strength of aggregate and binder, zinc phosphate modified steel fiber, silane coupling agent modified basalt fiber and polypropylene fiber are used for composite reinforcement. The different dispersion of the three fibers in concrete is used to form an interwoven complex three-dimensional network structure inside the concrete, which strengthens the combination of volcanic rock aggregate and cement colloid in the concrete, plays a prestressing effect, enhances the bonding force and friction between aggregates, and can effectively enhance the strength of the bonding points between ecological concrete aggregates, prevent the development of microcracks, reduce the brittleness of volcanic rock aggregates, and improve the toughness and bearing capacity of the nodes.

[0039] The modification of steel fibers with zinc phosphate is mainly divided into three steps. The first step: treating the steel fibers with NaOH solution to remove surface oil and rust, and pickling the steel fibers with HCl solution to remove surface organic matter and increase the surface roughness of the steel fibers. The second step: activating the steel fibers with H2O2 solution to enhance the bonding and biting ability between the steel fibers and the cement colloid. The third step: zinc phosphate coating on the surface of the steel fibers in a phosphating bath. Zinc phosphate microcrystals can improve the surface properties of the steel fibers and the adhesion properties of the interface contact area, provide a strong mechanical interlocking bond, enhance the cohesion of the concrete, improve the bonding strength between the steel fibers and the concrete, and enhance the toughness and tensile and compressive properties of the ecological concrete. In addition, a protective layer with adhesiveness will be formed on the surface of the steel fibers, which modifies and protects the surface of the steel fibers, improves the corrosion resistance of the steel fibers and the durability of the ecological concrete, and extends the service life of the concrete.

[0040] Modification of basalt fiber: Step 1: Ultrasonic treatment is used to disperse the basalt fiber. Heat treatment at 550°C is then performed to remove organic impurities from the basalt fiber surface. Step 2: Activation treatment of the basalt fiber with an HCl solution modifies the surface, promoting the regeneration of silanol groups and increasing surface roughness, facilitating the formation of an anchoring effect between the silane coupling agent and the grooves on the basalt fiber surface. Step 3: The activated basalt fiber is placed in a silane coupling agent solution. The hydrolyzed silanol groups form covalent bonds with the functional groups on the basalt surface. This creates a stable organic silicone coating on the basalt fiber surface, protecting it and improving its acid, alkali, and oxidation resistance. Furthermore, the silane coupling agent modification improves the hydrophilicity and adhesion of the basalt fiber, enhancing its dispersibility in concrete and its bonding with the cement matrix. At the same time, the interface structure between volcanic rock aggregates is improved, the bonding strength between aggregates is enhanced, and the bonding strength and tensile and compressive strength between basalt fiber and concrete are effectively improved.

[0041] 5. After curing for 28 days, the concrete specimens were thoroughly sprayed 3-5 times with a mixture of phosphoric and oxalic acids. These react with alkaline substances dissolved from the pores and surface of the eco-concrete. This improves the alkaline environment of the eco-concrete. The resulting calcium oxalate and calcium phosphate precipitates intertwine to form a thin layer covering the surface of the eco-concrete, preventing the dissolution of alkaline substances within the concrete. This maintains the pH of the soil within the eco-concrete pores within the pH range of 8-9, meeting the requirements for plant growth. This also reduces the environmental impact of alkali release from the concrete. Furthermore, the resulting calcium oxalate and calcium phosphate precipitates repair and strengthen the joints of the volcanic rock aggregate and further repair cracks, effectively enhancing the overall structural strength of the eco-concrete. The added wood organic charcoal has a certain adsorption capacity, which not only improves water purification performance but also effectively enhances the nutrient retention capacity of the eco-concrete, thereby strengthening its plant growth potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a test curve of the water retention performance of porous ceramsite. Implementation Method

[0043] The present invention is further described below with reference to specific examples. The nano-silicon dioxide particles used in the specific examples of this application have a particle size of 5-25 nm and a density of 2.15 g / cm 3 , with a specific surface area of ​​200m 2 / g; the steel fiber used in the zinc phosphate modified steel fiber is a steel fiber with a diameter of 0.2-0.3mm and a length of 15-30mm with a bent end; the basalt fiber has a diameter of 9-13μm and a length of 8-12mm; the polypropylene fiber has a diameter of 12-18μm and a length of 6-12mm; the cement used is PC 42.5 composite silicate cement (brand: Red Lion, manufacturer: Yunnan Hengli Plastic Industry Trading Co., Ltd.). Example 1

[0044] A slope protection ecological concrete comprises the following raw materials in parts by weight: 1000 parts of cement, 3650 parts of aggregate, 310 parts of water, 140 parts of mineral admixture, 8 parts of polyacrylate, 40 parts of hydroxypropyl methylcellulose, 12 parts of polycarboxylate water reducer, 12 parts of composite fiber, and 60 parts of wood activated carbon.

[0045] The above-mentioned mineral admixtures are a mixture of slag powder, fly ash, nano-silica and metakaolin in a weight ratio of 2:2:0.5:3; the composite fiber is a mixture of zinc phosphate modified steel fiber, silane coupling agent modified basalt fiber and polypropylene fiber in a mass ratio of 4:3:7.

[0046] The zinc phosphate modified steel fiber is prepared by the following steps:

[0047] (1) Immerse the steel fiber in a 0.1 M NaOH solution and heat it in a water bath at 55 °C for 1 min, then rinse it with distilled water for 1 min; then immerse it in a 0.1 M HCl solution and heat it in a water bath at 60 °C for 3 min, then rinse it with distilled water for 1.5 min;

[0048] (2) The pickled steel fibers were immersed in 0.01 M H2O2 solution and stirred for 2 min for activation, rinsed with distilled water for 3 min, and dried at an ambient temperature of 150 °C for 20 min;

[0049] (3) The activated steel fiber was immersed in a phosphating bath at 80°C for 50 min, rinsed with distilled water for 5 min, and then placed in an environment at 150°C for 20 min. After drying and solidification, zinc phosphate-modified steel fiber was obtained; 1L phosphating bath consisted of 0.6g Zn(NO3)2, 5g ZnO, 20ml 85% H3PO4, 0.2g CaO and distilled water.

[0050] The silane coupling agent modified basalt fiber is prepared by the following steps:

[0051] (1) Basalt fibers were placed in a 0.1 wt% sodium polyacrylate solution and stirred for 5 min (solid-liquid ratio of 1:10). The fibers were then dispersed by ultrasonic vibration at 700 W vibration power and 30 kHz frequency for 5 min. The fibers were then washed with distilled water for 3 min and filtered. The fibers were then heat treated at an ambient temperature of 550 °C for 40 min to remove organic impurities on the surface of the basalt fibers.

[0052] (2) The heat-treated basalt fibers were activated in 35 wt% concentrated HCl for 60 min (solid-to-liquid ratio of 1:5), washed with distilled water for 3 min, and dried at an ambient temperature of 150 °C for 15 min.

[0053] (3) The activated basalt fiber was immersed in an aminosilane coupling agent solution at room temperature for 8 minutes, filtered and drained, and then placed at an ambient temperature of 120°C for drying and curing for 40 minutes to obtain a silane coupling agent modified basalt fiber;

[0054] The aminosilane coupling agent solution is prepared by mixing γ-aminopropyltriethoxysilane, deionized water, and ethanol (99.7% purity) in a weight ratio of 1:2:8 and stirring for 30 minutes. The solid-to-liquid ratio during the immersion process in the aforementioned steel fiber and basalt fiber modification method is 1:9.

[0055] The wood activated carbon is made from eucalyptus chips. The eucalyptus chips are carbonized at 400°C for 60 minutes under N2 gas flow, and then the primary charcoal is activated with CO2 at 900°C for 90 minutes. After grinding, the particles with a size of ≤30 μm are screened for use.

[0056] The aggregate is made of volcanic rock and porous ceramsite in a weight ratio of 2:0.8, of which the volcanic rock particle size is 16-25mm, accounting for 1 / 2, and the bulk density is 1410kg / m 3 The particle size is 25-35mm, accounting for 1 / 2, and the bulk density is 1346kg / m 3 .

[0057] The porous ceramsite has a two-layer structure of an inner core layer and a coating layer, and is prepared by the following steps:

[0058] (1) The raw materials used for the inner core layer and the coating layer are the same, including the following components in parts by weight: 35 parts red mud, 30 parts fly ash, 10 parts glass fiber, 4 parts coal powder, 2 parts calcium carbonate whiskers, 4 parts activated alumina powder and 2 parts dextrin; the particle size of the coal powder in the raw material of the inner core layer is 70-150 μm, and the particle size of the coal powder in the raw material of the coating layer is 50-70 μm;

[0059] (2) After the raw materials of the inner core layer are evenly mixed, 30 wt% water is added to granulate to prepare an inner core with a particle size of 15 mm, and then the raw materials of the coating layer and 30 wt% of water of the coating layer raw materials are added to continue granulation to prepare raw material balls with a particle size of 20 mm, and then dried;

[0060] (3) Firing at 1200℃ for 20min and cooling in the furnace;

[0061] (4) The fired product is immersed in a 1.5wt% NaOH solution, kept at 80°C for 1-1.5 hours, and then washed and dried to obtain the product.

[0062] A preparation process of slope protection ecological concrete includes the following steps:

[0063] (1) Soak the aggregate for 24 hours and let it air dry naturally;

[0064] (2) The mineral admixture, 1 / 2 of the water, and the aggregate were mixed and stirred for 3 minutes to obtain premix A; the cement and the composite fiber were mixed and stirred for 2 minutes, and the composite fiber was added three times (one-third each time), with the first stirring for 0.5 minutes, the second stirring for 0.5 minutes, and the third stirring for 1 minute to obtain premix B; the premix A and premix B were then mixed and stirred for 1 minute to obtain a mixed slurry C;

[0065] (3) Add polycarboxylate water reducer, polyacrylate and hydroxypropyl methylcellulose to the mixed slurry C, and add the remaining 1 / 2 of water and wood activated carbon, and mix and stir for 3 minutes; after stirring evenly, use a tamping rod to tamp 30 times from the four sides to the middle in three times, and press into shape at 0.3MPa, and send it to the standard curing room for curing for 28 days;

[0066] (4) The cured concrete was sprayed with a mixed acid of 2 wt% phosphoric acid and 2 wt% oxalic acid in a ratio of 1:1 four times at intervals of 24 h (to moisten the concrete surface) to obtain slope protection ecological concrete. Example 2

[0067] A slope protection ecological concrete comprises the following raw materials in parts by weight: 1020 parts of cement, 3700 parts of aggregate, 320 parts of water, 145 parts of mineral admixture, 8.4 parts of polyacrylate, 41 parts of hydroxypropyl methylcellulose, 12.2 parts of polycarboxylate water reducer, 12.5 parts of composite fiber, and 62 parts of wood activated carbon.

[0068] The above-mentioned mineral admixtures are a mixture of slag powder, fly ash, nano-silica and metakaolin in a weight ratio of 2.2:2:0.5:3; the composite fiber is a mixture of zinc phosphate modified steel fiber, silane coupling agent modified basalt fiber and polypropylene fiber in a mass ratio of 4.5:3:7.

[0069] The zinc phosphate modified steel fiber is prepared by the following steps:

[0070] (1) Immerse the steel fiber in a 0.1 M NaOH solution and heat it in a water bath at 55 °C for 2 min, then rinse it with distilled water for 1 min; then immerse it in a 0.1 M HCl solution and heat it in a water bath at 60 °C for 5 min, then rinse it with distilled water for 1.5 min;

[0071] (2) The pickled steel fibers were immersed in a 0.01 M H2O2 solution and stirred for 3 min for activation, rinsed with distilled water for 3 min, and dried at an ambient temperature of 150 °C for 20 min;

[0072] (3) The activated steel fiber was immersed in a phosphating bath at 80°C for 60 min, rinsed with distilled water for 5 min, and then placed in an environment at 150°C for 20 min. After drying and solidification, zinc phosphate-modified steel fiber was obtained; 1L phosphating bath consisted of 0.6g Zn(NO3)2, 5g ZnO, 22ml 85% H3PO4, 0.2g CaO and distilled water.

[0073] The silane coupling agent modified basalt fiber is prepared by the following steps:

[0074] (1) Basalt fibers were placed in a 0.15 wt% sodium polyacrylate solution and stirred for 5 min (solid-to-liquid ratio of 1:10). The fibers were then dispersed by ultrasonic vibration at a power of 700 W and a frequency of 30 kHz for 8 min. The fibers were washed with distilled water for 3 min and filtered. The fibers were then heat treated at an ambient temperature of 550 °C for 45 min to remove organic impurities on the surface of the basalt fibers.

[0075] (2) The heat-treated basalt fibers were activated in a 35 wt% concentrated HCl solution for 60 min (solid-to-liquid ratio of 1:5), washed with distilled water for 3 min, and dried at an ambient temperature of 150 °C for 20 min.

[0076] (3) Immersing the activated basalt fiber in an aminosilane coupling agent solution at room temperature for 10 minutes, filtering and draining the solution, and then drying and curing the solution at an ambient temperature of 120°C for 60 minutes to obtain a silane coupling agent-modified basalt fiber;

[0077] The aminosilane coupling agent solution is prepared by mixing γ-aminopropyltriethoxysilane, deionized water and ethanol (purity of 99.7%) in a weight ratio of 1:4:10 and stirring for 30 minutes.

[0078] The aggregate is a mixture of volcanic rock and porous ceramsite in a weight ratio of 2:0.8; the volcanic rock particle size in the aggregate is 16-25mm, accounting for 1 / 2, and the bulk density is 1410kg / m 3 The particle size is 25-35mm, accounting for 1 / 2, and the bulk density is 1346kg / m 3 . .

[0079] The porous ceramsite has a two-layer structure of an inner core layer and a coating layer, and is prepared by the following steps:

[0080] (1) The raw materials used for the inner core layer and the coating layer are the same, including the following components in parts by weight: 36 parts red mud, 31 parts fly ash, 11 parts glass fiber, 4.5 parts coal powder, 2.2 parts calcium carbonate whiskers, 4.5 parts activated alumina and 2.5 parts dextrin; the particle size of the coal powder in the raw material of the inner core layer is 70-150 μm, and the particle size of the coal powder in the raw material of the coating layer is 50-70 μm;

[0081] (2) After the raw materials of the inner core layer are mixed evenly, 30 wt% water is added to granulate to prepare an inner core with a particle size of 15 mm, and then the raw materials of the coating layer and 30 wt% water are added to continue granulation to prepare raw material balls with a particle size of 20 mm, and then dried;

[0082] (3) Firing at 1200℃ for 20min and cooling in the furnace;

[0083] (4) The fired product was immersed in a 2 wt% NaOH solution, kept at 80°C for 1.5 h, and then washed and dried to obtain the product.

[0084] A preparation process of slope protection ecological concrete includes the following steps:

[0085] (1) Soak the aggregate for 24 hours and let it air dry naturally;

[0086] (2) The mineral admixture, 1 / 2 of the water, and the aggregate were mixed and stirred for 3 minutes to obtain premix A; the cement and the composite fiber were mixed and stirred for 2 minutes, and the composite fiber was added three times, with the first stirring time of 0.5 minutes, the second stirring time of 0.5 minutes, and the third stirring time of 1 minute to obtain premix B; the premix A and premix B were mixed and stirred for 1 minute to obtain a mixed slurry C;

[0087] (3) Add polycarboxylate water reducer, polyacrylate and hydroxypropyl methylcellulose to the mixed slurry C, and add the remaining 1 / 2 of water and wood activated carbon, and mix and stir for 3 minutes; after stirring evenly, use a tamping rod to tamp 35 times from the four sides to the middle in three layers, and press into shape at 0.5 MPa, and send it to a standard curing room for curing for 28 days;

[0088] (4) The cured concrete was sprayed four times with a mixture of 2 wt% phosphoric acid and 2 wt% oxalic acid in a ratio of 1:1 at intervals of 24 h to obtain slope protection ecological concrete.

[0089] The rest of the process is the same as in Example 1. Example 3

[0090] A slope protection ecological concrete comprises the following raw materials in parts by weight: 1040 parts of cement, 3750 parts of aggregate, 330 parts of water, 150 parts of mineral admixture, 8.8 parts of polyacrylate, 43 parts of hydroxypropyl methylcellulose, 12.4 parts of polycarboxylate water reducer, 13 parts of composite fiber, and 64 parts of wood activated carbon.

[0091] The above-mentioned mineral admixtures are a mixture of slag powder, fly ash, nano-silica and metakaolin in a weight ratio of 2.5:2:0.5:3; the composite fiber is a mixture of zinc phosphate modified steel fiber, silane coupling agent modified basalt fiber and polypropylene fiber in a mass ratio of 5:3:7.

[0092] The zinc phosphate modified steel fiber is prepared by the following steps:

[0093] (1) Immerse the steel fiber in a 0.1 M NaOH solution and heat it in a water bath at 55 °C for 2 min, then rinse it with distilled water for 1 min; then immerse it in a 0.1 M HCl solution and heat it in a water bath at 60 °C for 5 min, then rinse it with distilled water for 1.5 min;

[0094] (2) The pickled steel fibers were immersed in a 0.01 M H2O2 solution and stirred for 3 min for activation, rinsed with distilled water for 3 min, and dried at an ambient temperature of 150 °C for 20 min;

[0095] (3) The activated steel fiber was immersed in a phosphating bath at 80°C for 60 min, rinsed with distilled water for 5 min, and then placed in an environment at 150°C for 20 min. After drying and solidification, zinc phosphate-modified steel fiber was obtained; 1L phosphating bath consisted of 0.6g Zn(NO3)2, 5g ZnO, 20ml 85% H3PO4, 0.2g CaO and distilled water.

[0096] The silane coupling agent modified basalt fiber is prepared by the following steps:

[0097] (1) Basalt fibers were placed in a 0.15 wt% sodium polyacrylate solution and stirred for 5 min (solid-to-liquid ratio of 1:10). The fibers were then dispersed using ultrasonic vibration at a power of 700 W and a frequency of 30 kHz for 8 min. The fibers were then washed with distilled water for 3 min and filtered. The fibers were then heat treated at an ambient temperature of 550 °C for 45 min to remove organic impurities on the surface of the basalt fibers.

[0098] (2) The heat-treated basalt fibers were activated in a 35 wt% concentrated HCl solution for 60 min (solid-to-liquid ratio of 1:5), washed with distilled water for 3 min, and dried at an ambient temperature of 150 °C for 20 min.

[0099] (3) Immersing the activated basalt fiber in an aminosilane coupling agent solution at room temperature for 10 minutes, filtering and draining the solution, and then drying and curing the solution at an ambient temperature of 120°C for 50 minutes to obtain a silane coupling agent-modified basalt fiber;

[0100] The aminosilane coupling agent solution is prepared by mixing γ-aminopropyltriethoxysilane, deionized water and ethanol (purity of 99.7%) in a weight ratio of 1:3:9 and stirring for 30 minutes.

[0101] The aggregate is made of volcanic rock and porous ceramsite in a weight ratio of 2:0.8. The volcanic rock particle size in the aggregate is 16-25mm, accounting for 1 / 2, and the bulk density is 1410kg / m 3 The particle size is 25-35mm, accounting for 1 / 2, and the bulk density is 1346kg / m 3 .

[0102] The porous ceramsite has a two-layer structure of an inner core layer and a coating layer, and is prepared by the following steps:

[0103] (1) The raw materials used for the inner core layer and the coating layer are the same, including the following components in parts by weight: 38 parts red mud, 32 parts fly ash, 12 parts glass fiber, 5 parts coal powder, 2.5 parts calcium carbonate whiskers, 5 parts activated alumina and 3 parts dextrin; the particle size of the coal powder in the raw material of the inner core layer is 70-150 μm, and the particle size of the coal powder in the raw material of the coating layer is 50-70 μm;

[0104] (2) After the raw materials of the inner core layer are evenly mixed, 30 wt% water is added to granulate to prepare an inner core with a particle size of 15 mm, and then the raw materials of the coating layer and 30 wt% water of the coating layer raw materials are added to continue granulation to prepare raw material balls with a particle size of 20 mm, and then dried;

[0105] (3) Firing at 1200℃ for 20min and cooling in the furnace;

[0106] (4) The fired product is immersed in a 2 wt% NaOH solution, kept at 80°C for 1-1.5 hours, and then washed and dried to obtain the product.

[0107] A preparation process of slope protection ecological concrete includes the following steps:

[0108] (1) Soak the aggregate for 24 hours and let it air dry naturally;

[0109] (2) The mineral admixture, 1 / 2 of the water, and the aggregate were mixed and stirred for 3 minutes to obtain premix A; the cement and the composite fiber were mixed and stirred for 2 minutes, and the composite fiber was added three times, with the first stirring time of 0.5 minutes, the second stirring time of 0.5 minutes, and the third stirring time of 1 minute to obtain premix B; the premix A and premix B were mixed and stirred for 1 minute to obtain a mixed slurry C;

[0110] (3) Add polycarboxylate water reducer, polyacrylate and hydroxypropyl methylcellulose to the mixed slurry C, and add the remaining 1 / 2 of water and wood activated carbon, and mix and stir for 3 minutes; after stirring evenly, use a tamping rod to tamp 30 times from the four sides to the middle in three times, and press it into shape at 0.4MPa, and send it to the standard curing room for curing for 28 days;

[0111] (4) The cured concrete was sprayed four times with a mixture of 2 wt% phosphoric acid and 2 wt% oxalic acid in a ratio of 1:1 at intervals of 24 h to obtain slope protection ecological concrete.

[0112] The other processes are the same as those in Example 2. Example 4

[0113] A slope protection ecological concrete comprises the following raw materials in parts by weight: 1060 parts of cement, 3800 parts of aggregate, 340 parts of water, 155 parts of mineral admixture, 9.2 parts of polyacrylate, 44 parts of hydroxypropyl methylcellulose, 12.6 parts of polycarboxylate water reducer, 13.5 parts of composite fiber, and 66 parts of wood activated carbon.

[0114] The above-mentioned mineral admixtures are a mixture of slag powder, fly ash, nano-silica and metakaolin in a weight ratio of 3:2:0.5:3; the composite fiber is a mixture of zinc phosphate modified steel fiber, silane coupling agent modified basalt fiber and polypropylene fiber in a mass ratio of 5:3:7.

[0115] The aggregate is made of volcanic rock and porous ceramsite in a weight ratio of 2:0.8. The volcanic rock particle size in the aggregate is 16-25mm, accounting for 1 / 2, and the bulk density is 1410kg / m 3 The particle size is 25-35mm, accounting for 1 / 2, and the bulk density is 1346kg / m 3 .

[0116] The porous ceramsite has a two-layer structure of an inner core layer and a coating layer, and is prepared by the following steps:

[0117] (1) The raw materials used for the inner core layer and the coating layer are the same, including the following components in parts by weight: 40 parts red mud, 33 parts fly ash, 11 parts glass fiber, 5 parts coal powder, 2.5 parts calcium carbonate whiskers, 6 parts activated alumina and 3 parts dextrin; the particle size of the coal powder in the raw material of the inner core layer is 70-150 μm, and the particle size of the coal powder in the raw material of the coating layer is 50-70 μm;

[0118] (2) After the raw materials of the inner core layer are mixed evenly, 30 wt% water is added to granulate to prepare an inner core with a particle size of 15 mm, and then the raw materials of the coating layer are added to continue granulation to prepare raw material balls with a particle size of 20 mm, and then dried;

[0119] (3) Firing at 1200℃ for 20min and cooling in the furnace;

[0120] (4) The fired product is immersed in a 2 wt% NaOH solution, kept at 80°C for 1-1.5 hours, and then washed and dried to obtain the product.

[0121] The other processes are the same as those in Example 3. Example 5

[0122] A slope protection ecological concrete comprises the following raw materials in parts by weight: 1080 parts of cement, 3850 parts of aggregate, 350 parts of water, 160 parts of mineral admixture, 9.6 parts of polyacrylate, 45 parts of hydroxypropyl methylcellulose, 12.8 parts of polycarboxylate water reducer, 14 parts of composite fiber, and 68 parts of wood activated carbon.

[0123] The above-mentioned mineral admixtures are a mixture of slag powder, fly ash, nano-silica and metakaolin in a weight ratio of 3:2:0.5:3; the composite fiber is a mixture of zinc phosphate modified steel fiber, silane coupling agent modified basalt fiber and polypropylene fiber in a mass ratio of 5:3:7.

[0124] The aggregate is a mixture of volcanic rock and porous expanded clay in a weight ratio of 2:0.8.

[0125] The porous ceramsite has a two-layer structure of an inner core layer and a coating layer, and is prepared by the following steps:

[0126] (1) The raw materials used for the inner core layer and the coating layer are the same, including the following components in parts by weight: 40 parts red mud, 35 parts fly ash, 12 parts glass fiber, 5 parts coal powder, 3 parts calcium carbonate whiskers, 6 parts activated alumina and 3 parts dextrin; the particle size of the coal powder in the raw material of the inner core layer is 70-150 μm, and the particle size of the coal powder in the raw material of the coating layer is 50-70 μm;

[0127] (2) After the raw materials of the inner core layer are mixed evenly, 30 wt% water is added to granulate to prepare an inner core with a particle size of 15 mm, and then the raw materials of the coating layer are added to continue granulation to prepare raw material balls with a particle size of 20 mm, and then dried;

[0128] (3) Firing at 1200℃ for 20min and cooling in the furnace;

[0129] (4) The fired product is immersed in a 1.5wt% NaOH solution, kept at 80°C for 1-1.5 hours, and then washed and dried to obtain the product.

[0130] The other processes are the same as those in Example 3.

[0131] Comparative Example 1

[0132] Comparative Example 1 is a comparative example of Example 5, and differs from Example 5 in that the porous ceramsite is not granulated in layers.

[0133] The specific method is: porous ceramsite is prepared by the following steps:

[0134] (1) Ingredients: The raw materials include the following parts by weight: 40 parts red mud, 35 parts fly ash, 12 parts glass fiber, 5 parts coal powder, 3 parts calcium carbonate whisker, 6 parts activated alumina and 3 parts dextrin. The particle size of the coal powder is 70-150 μm.

[0135] (2) After mixing the raw materials, add 30 wt% water to granulate into raw material balls with a particle size of 20 mm, and dry them;

[0136] (3) Firing at 1200℃ for 20min and cooling in the furnace;

[0137] (4) The fired product is immersed in a 1.5wt% NaOH solution, kept at 80°C for 1-1.5 hours, and then washed and dried to obtain the product.

[0138] Comparative Example 2

[0139] The difference between Comparative Example 2 and Example 5 is that the calcium carbonate whiskers in the porous ceramsite ingredients are replaced by coal powder.

[0140] Comparative Example 3

[0141] The difference between Comparative Example 3 and Example 5 is that the aggregate is volcanic rock and porous ceramsite is not compounded.

[0142] Comparative Example 4

[0143] The difference between Comparative Example 4 and Example 5 is that no composite fiber is added to the slope protection concrete.

[0144] Comparative Example 5

[0145] The difference between Comparative Example 5 and Example 5 is that the raw materials in the composite fiber are not modified:

[0146] That is, the composite fiber is a mixture of steel fiber, basalt fiber and polypropylene fiber in a mass ratio of 5:3:7.

[0147] Comparative Example 6

[0148] The difference between Comparative Example 6 and Example 5 is that the cured concrete was not sprayed with mixed acid for alkali reduction treatment.

[0149] Comparative Example 7

[0150] The difference between Comparative Example 7 and Example 5 is that the mineral admixture in the slope protection ecological concrete is replaced by an equal amount of cement.

[0151] Performance testing

[0152] 1. The porosity and compressive strength (MPa) of the porous ceramsite prepared in Examples 1-5 and Comparative Examples 1-2 were tested.

[0153] 2. The water retention performance of the porous ceramsite prepared in Examples 1-5 and Comparative Examples 1-2 was tested. The specific test method was as follows: the porous ceramsite was immersed in water for 24 hours (the difference in mass before and after water infusion was the water absorption), and then dried at a humidity of 45% and 50°C. The water loss rate was calculated by weighing at regular intervals until it was dried to a constant weight. The time it took to dry to a constant weight was the final water retention time. The results are shown in Table 1. Figure 1 .

[0154] 3. The slope protection ecological concrete specimens prepared in Examples 1-5 and Comparative Examples 1-7 were subjected to performance tests and vegetation experiments to detect their compressive strength, pH value after alkali reduction, porosity, water absorption rate, vegetation, water purification performance and durability; the compressive strength was determined by referring to GB / T50081-2019 "Standard for Test Methods for Physical and Mechanical Properties of Concrete".

[0155] pH value test after alkali reduction: Place the specimen in a bucket, add 12L of distilled water and stir to expel the air in the pores, soak for 24 hours, fully stir the specimen leaching solution and then test the pH value.

[0156] Porosity test: First measure the apparent volume V of the concrete specimen, immerse the specimen in water at room temperature for 24 hours until no bubbles are found when shaken, and weigh the mass M1 of the specimen suspended in the water using a hydrostatic electronic balance. Remove the specimen and drain it until no water drips from the bottom. Wipe the surface of the specimen dry and weigh its mass M2. The porosity of the specimen = (1-(M2-M1) / ρ 水 V)*100%.

[0157] Vegetation test: Outdoor planting tests were conducted. Screened seeds were first soaked in clean water for 24 hours. River mud, organic fertilizer, and peat nutrient soil (purchased from Shandong Chenchen Biotechnology Co., Ltd.) were then laid onto cured 150 x 150 x 40 mm concrete slabs to a thickness of 3-4 cm. Each concrete slab was then planted with soaked white wool grass seeds and covered with 2-3 cm of soil. Watering was performed daily before germination and every other day thereafter. While the seeds germinated around the same time in all groups around 4 days, significant differences in plant height were observed around 10 days after germination. The heights of the white wool grass plants at 28 days of age are shown in Table 1.

[0158] Static water purification test: Nine groups of test blocks with a size of 150*150*150mm were placed in seven drums filled with sewage, with a total sewage volume of 20L. The test drums were placed in a ventilated indoor environment. The total nitrogen and total phosphorus concentrations were measured before and after the test, and the average removal rate was calculated. The test time was 720h. The test results are shown in Table 1.

[0159] Durability test: refer to the sulfate erosion resistance test method specified in the Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete (GB / T50082-2009), and conduct 8 cycles of accelerated dry-wet cycles on concrete specimens (immerse the concrete specimens in 5wt% NaSO4 solution for 48 hours, take them out and air dry them for 1 hour, then dry them in an 80℃ oven for 18 hours, and cool them naturally for 4 hours, which is one cycle. Two cycles constitute one cycle, and a new 5wt% NaSO4 solution must be used in each cycle). The mass loss rate (M), compressive strength corrosion resistance coefficient (K f ), relative transverse dynamic elastic modulus (P) to characterize the sulfate attack resistance of concrete. The test results of 8 cycles are shown in Table 1.

[0160] Table 1 Performance test data

[0161]

[0162] From Table 1 and Figure 1As can be seen, the porous ceramsite prepared in Examples 1-5 of the present application has a high porosity, a certain compressive strength, and excellent water retention, with a water retention time of 48-50 hours. This indicates that the porous ceramsite prepared in the present application has a large number of interconnected microporous structures, which can achieve slow evaporation and release of water. The water retention time of Comparative Examples 1-2 is lower than that of Example 5 (39 hours for Comparative Example 1 and 42 hours for Comparative Example 2), indicating that the two-layer structure design of the present application can improve the water retention of the porous ceramsite. In addition, the calcium carbonate whiskers and other porogens in the porous ceramsite synergistically form small, evenly distributed interconnected voids in the porous ceramsite, thereby enhancing water retention.

[0163] Combined with the test results of the slope protection ecological concrete, it can be seen that the slope protection ecological concrete prepared in this application has high strength and a compressive strength of 12.2-15.1MPa. On the basis of meeting the slope protection requirements well, its porosity is 23.6-28.5%, the water absorption rate is 10.2-10.6%, the vegetation performance is excellent, and it also has an excellent water purification effect.

[0164] Comparative Examples 1-2 are comparative examples of Example 5, wherein the porous expanded clay in Comparative Example 1 is not layered and granulated, and the calcium carbonate whiskers in Comparative Example 2 are replaced with coal powder. The water retention time of the prepared porous expanded clay is lower than that of Example 5, and the water absorption rate of the slope protection ecological concrete prepared accordingly is also relatively low, and its plant growth height and water purification effect are lower than those of Example 5, indicating that the porous expanded clay designed in this application can improve the plant growth and water purification effect of concrete.

[0165] Combining the data of Comparative Examples 3-5, it can be seen that the aggregate in Comparative Example 3 is volcanic rock, and its compressive strength is improved, but its water absorption rate, vegetative property and water purification effect are far lower than those of Example 5. In Comparative Example 4, no composite fiber is added, and its compressive strength is lower than that of Example 5; the composite fiber in Comparative Example 5 is not modified, and its strength is higher than that of Comparative Example 4. As for Example 5, it shows that the modification of the composite fiber can indeed improve the strength of the interface transition area between the aggregate and the binder. Comparative Example 6 did not perform alkali reduction treatment on the concrete cured for 28 days, and its pH value was significantly higher than that of Example 5 with alkali reduction treatment, and its vegetative ability was significantly weaker than that of Example 5. It can be seen that the present invention's alkali reduction treatment by spraying acidic solution can effectively improve the vegetative ability of slope protection ecological concrete. In Comparative Example 5, the mineral admixture is replaced by an equal amount of cement, and its compressive strength is lower than that of Example 5, which shows that the mineral admixture used in this application can increase the strength of ecological concrete to a certain extent.

[0166] In addition, combined with the durability test data, it can be seen that the mass loss rate of Examples 4-5 and Comparative Example 7 is significantly higher than that of Example 5, and the compressive strength corrosion resistance coefficient and the relative lateral dynamic elastic modulus are significantly lower than those of Example 5, indicating that the addition of mixed fibers, mineral admixtures and composite fibers in this application can indeed effectively improve the durability of ecological slope protection concrete.

[0167] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not limiting. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A slope protection ecological concrete, characterized by: The raw materials include the following parts by weight: 1000-1080 parts of cement, 3650-3850 parts of aggregate, 310-350 parts of water, 140-160 parts of mineral admixture, 8-9.6 parts of polyacrylate, 40-45 parts of hydroxypropyl methylcellulose, 12-12.8 parts of polycarboxylate water reducer, 12-14 parts of composite fiber, and 60-68 parts of wood activated carbon; The aggregate is a mixture of volcanic rock and porous ceramsite in a weight ratio of 2:0.5-1; The porous ceramsite has a two-layer structure of an inner core layer and a coating layer, and is prepared by the following steps: (1) The raw materials used for the inner core layer and the coating layer are the same, including the following components in parts by weight: 35-40 parts of red mud, 30-35 parts of fly ash, 10-12 parts of glass fiber, 4-5 parts of coal powder, 2-3 parts of calcium carbonate whiskers, 4-6 parts of activated alumina and 2-3 parts of dextrin; the particle size of the coal powder in the raw material of the inner core layer is 70-150 μm, and the particle size of the coal powder in the raw material of the coating layer is 50-70 μm; (2) After the raw materials of the inner core layer are mixed evenly, water is added to granulate to prepare an inner core with a particle size of 15 mm, and then the raw materials of the coating layer are added to continue granulation to prepare raw material balls with a particle size of 20 mm, and then dried; (3) Firing at 1200℃ for 15-20min and cooling in the furnace; (4) The fired product is immersed in a 1.5-2wt% NaOH solution, kept at 80°C for 1-1.5 hours, and then washed and dried to obtain the product.

2. The slope protection ecological concrete according to claim 1, characterized in that: The mineral admixture is a mixture of slag powder, fly ash, nano silicon dioxide and metakaolin in a weight ratio of 2-3:2:0.5:

3.

3. The slope protection ecological concrete according to claim 1, characterized in that: The composite fiber is formed by mixing zinc phosphate modified steel fiber, silane coupling agent modified basalt fiber and polypropylene fiber in a mass ratio of 4-5:3:

7.

4. The slope protection ecological concrete according to claim 3, characterized in that: The zinc phosphate modified steel fiber is prepared by the following steps: (1) Immerse the steel fiber in a 0.1M NaOH solution and heat it in a water bath at 55°C for 1-2 minutes, then rinse it with distilled water; then immerse it in a 0.1M HCl solution and heat it in a water bath at 60°C for 3-5 minutes, then rinse it with distilled water; (2) Immerse the pickled steel fiber in 0.01M H2O2 solution and stir for 2-3 minutes for activation treatment, rinse with distilled water, and dry at 150°C; (3) Immerse the activated steel fiber in a phosphating bath at 80°C for 50-60 minutes, rinse with distilled water, and then place it in an environment at 150°C for 20 minutes. After drying and solidification, zinc phosphate-modified steel fiber is obtained; 1L of the phosphating bath consists of 0.6g Zn(NO3)2, 5g ZnO, 18-22ml 85% H3PO4, 0.2g CaO and distilled water.

5. The slope protection ecological concrete according to claim 3, characterized in that: The silane coupling agent modified basalt fiber is prepared by the following steps: (1) Place basalt fiber in 0.1-0.15wt% sodium polyacrylate solution, stir evenly, disperse by ultrasonic for 5-8 minutes, rinse with distilled water, and heat treat at 550℃ for 40-45 minutes; (2) Activate the heat-treated basalt fiber in concentrated hydrochloric acid for 60 minutes, rinse with distilled water, and dry at an ambient temperature of 150°C for 15-20 minutes; (3) Immersing the activated basalt fiber in an aminosilane coupling agent solution for 8-12 minutes, filtering and draining the solution, and then drying and curing the solution at an ambient temperature of 120°C for 40-60 minutes to obtain a silane coupling agent-modified basalt fiber; The aminosilane coupling agent solution is prepared by mixing γ-aminopropyltriethoxysilane, deionized water and ethanol in a weight ratio of 1:2-4:8-10.

6. The slope protection ecological concrete according to claim 1, characterized in that: The wood activated carbon is made of eucalyptus chips. The eucalyptus chips are carbonized at 400°C for 60 minutes under N2 gas flow, and then the primary charcoal is activated with CO2 at 900°C for 90 minutes. After grinding, particles with a diameter of ≤30 μm are screened for use.

7. The slope protection ecological concrete according to claim 1, characterized in that: The volcanic rock has a particle size of 16-25 mm, accounting for 1 / 2, and a bulk density of 1410 kg / m 3 The particle size is 25-35mm, accounting for 1 / 2, and the bulk density is 1346kg / m 3 .

8. A process for preparing the slope protection ecological concrete according to claim 1, characterized in that: The following steps are involved: (1) Soak the aggregate for 24 hours and let it air dry naturally; (2) The mineral admixture, 1 / 2 of the water, and the aggregate were mixed and stirred for 3 minutes to obtain premix A; the cement and the composite fiber were mixed and stirred for 2 minutes, and the composite fiber was added three times, with the first stirring time of 0.5 minutes, the second stirring time of 0.5 minutes, and the third stirring time of 1 minute to obtain premix B; the premix A and premix B were mixed and stirred for 1 minute to obtain a mixed slurry C; (3) Add polycarboxylate water reducer, polyacrylate and hydroxypropyl methylcellulose to the mixed slurry C, and add the remaining 1 / 2 of water and wood activated carbon, mix and stir for 3 minutes; after stirring evenly, use a tamping rod to tamp 25-35 times from the periphery to the middle layer by layer for 3 times, and press into shape at 0.3-0.5MPa, and send it to a standard curing room for curing for 28 days; (4) The cured concrete is sprayed 3-5 times with a mixed acid consisting of 2-3 wt% phosphoric acid and 2-3 wt% oxalic acid in a ratio of 1:1 at intervals of 24 hours to obtain slope protection ecological concrete.

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