Slope protection cement blanket and preparation method thereof

Abstract

The invention relates to the technical field of slope protection cement materials, in particular to a slope protection cement blanket and a preparation method thereof. The main body of the slope protection cement blanket is made of a cement solid-phase material; the cement solid-phase material is prepared from the following raw materials in parts by weight: 25 to 35 parts of low-alkali sulphoaluminate cement, 5 to 10 parts of metakaolin, 10 to 18 parts of coconut soil, 25 to 40 parts of washed sand, 3 to 8 parts of modified asphalt, 0.5 to 2 parts of sodium carboxymethyl cellulose, 0.5 to 2 parts of polyvinyl alcohol chopped fiber, 0.5 to 2 parts of polyvinyl alcohol long fiber and 5 to 10 parts of water retention resin. According to the slope protection cement blanket, the raw material composition of the cement solid-phase material is designed, so that the slope protection cement blanket obtains good vegetation performance on the basis of meeting the mechanical property required by slope protection.

Description

Technical Field

[0001] This invention relates to the technical field of slope protection cement materials, specifically to a slope protection cement blanket and its preparation method. Background Technology

[0002] During the construction of infrastructure such as transportation, water conservancy, and mining, a large number of exposed slopes are formed. Due to their loose soil structure and lack of vegetation cover, these slopes are prone to landslides, collapses, and soil erosion under the influence of natural factors such as rainfall, weathering, and earthquakes. This not only threatens the safety of the engineering structure and the surrounding environment, but also disrupts the regional ecological balance, leading to a series of environmental problems such as soil degradation and reduced biodiversity. Therefore, slope protection has become a key issue that urgently needs to be addressed in the fields of engineering construction and ecological restoration.

[0003] The core objective of slope protection technology is to achieve ecological restoration and sustainable development while ensuring the mechanical stability of the slope. Traditional slope protection technologies mostly use rigid structures such as masonry, shotcrete, and masonry retaining walls. Although these structures can resist external erosion and maintain the physical stability of the slope in the short term, they have obvious drawbacks, such as poor adaptability to complex terrain and susceptibility to cracks caused by natural settlement of the slope soil or temperature changes, thus losing their protective function. More importantly, rigid structures completely block the soil environment required for vegetation growth, making long-term ecological restoration of the slope impossible.

[0004] Ecological slope protection technology not only requires sufficient mechanical properties, such as compressive strength, shear strength, and erosion resistance, to resist slope erosion and soil slippage, but also needs to provide a suitable environment for plant growth, including a reasonable pore structure, water retention, air permeability, and necessary nutrient conditions. Plant roots can penetrate deep into the interior of ecological slope protection materials, enhancing the bonding between the materials and the slope soil, further improving slope stability; plant stems and leaves can slow down surface runoff, weaken the kinetic energy of rainfall splash, and reduce the erosion of the slope by water flow; at the same time, vegetation cover can improve the regional microclimate, promote the accumulation of soil organic matter, gradually restore the ecological function of the slope, and achieve the coordinated development of slope protection and ecological restoration.

[0005] Composite flexible concrete blankets, or cement blankets for short, are typically composed of cement, fiber reinforcement materials, aggregates, and additives such as water-retaining agents and water-reducing agents. Their core characteristic is that in their dry state, they are flexible rolls that can be flexibly cut and laid according to the slope and shape of the slope, requiring no complex construction equipment. When exposed to water, the cement and other binding materials quickly hydrate and solidify, forming a protective layer with a certain strength and flexibility. Currently, cement blankets are widely used in various scenarios such as highway slope protection, riverbank treatment, mine ecological restoration, and railway slope reinforcement, becoming one of the important materials in the field of slope protection.

[0006] In recent years, domestic and international research institutions and enterprises have conducted extensive research on the performance optimization of cement blankets. However, most studies have focused on improving mechanical properties and ease of construction, with significant shortcomings in the systematic optimization of vegetation performance. For example, CN119195069 A discloses a flexible concrete blanket for ditch protection. This flexible concrete blanket includes a permeable fabric in the upper fabric layer, a waterproof fabric in the lower fabric layer, and a cement solid phase filler and flat fibers or fabrics between the permeable and waterproof fabrics. The permeable and waterproof fabrics are connected by several spaced-apart stitching fibers. This technical solution, by adding flat fibers or fabrics to the cement solid phase filler, can, on the one hand, sew and fix the flat fibers or fabrics under the action of the stitching fibers, strengthening the binding and fixing effect on the cement solid phase filler, while reducing the stitching density, thereby improving the flexibility of the concrete blanket. On the other hand, the flat fibers or fabrics can act as a reinforcing phase to improve the strength of the concrete blanket. This technical solution mainly compares the influence of fibers with different cross-sections on the strength of the concrete blanket.

[0007] For example, CN 219153866 U discloses a cement-based woven fiber blanket for erosion protection. The thickness of the cement-based woven fiber blanket is 1-5 cm, and it includes, from top to bottom, a mesh surface layer, a stainless steel wire mesh layer, 3D alkali-resistant glass fiber, a plastic geotextile layer, and a protective isolation layer. The plastic geotextile layer and the isolation layer are bonded together with an adhesive. The 3D alkali-resistant glass fiber consists of uniformly distributed filaments forming uniformly distributed cylinders and hexagons, containing uniformly distributed fly ash, cement, and dry concrete powder. This technical solution uses glass fiber, which can easily sever the plant roots wrapped around it when plants grow, affecting plant growth.

[0008] Therefore, developing a slope protection cement blanket that can balance high mechanical properties and vegetation performance, and achieving simultaneous improvement of mechanical and vegetation performance through reasonable component design and structural optimization, has become an important problem that urgently needs to be solved. Summary of the Invention

[0009] To address the technical problem that existing slope protection cement blankets rarely consider vegetation performance, this invention provides a slope protection cement blanket and its preparation method. This invention designs the raw material composition of the cement solid phase material, enabling the slope protection cement blanket to achieve good vegetation performance while meeting the mechanical properties required for slope protection.

[0010] The technical solution of this invention is as follows: In a first aspect, the present invention provides a slope protection cement blanket, the main body of which is a cement solid phase material; the raw materials of the cement solid phase material include, by weight: 25 - 35 parts of low - alkali sulphoaluminate cement, 5 - 10 parts of metakaolin, 10 - 18 parts of coconut soil, 25 - 40 parts of washed sand, 3 - 8 parts of modified asphalt, 0.5 - 2 parts of sodium carboxymethyl cellulose, 0.5 - 2 parts of short - cut polyvinyl alcohol fibers, 0.5 - 2 parts of long polyvinyl alcohol fibers, 5 - 10 parts of water - retaining resin, Among them, the washed sand is composed of coarse sand, medium sand and fine sand according to the mass ratio of 3:4:3. The particle size D1 of the coarse sand satisfies 0.6mm < D1 ≤ 2.36mm, the particle size D2 of the medium sand satisfies 0.3mm < D2 ≤ 0.6mm, and the particle size D2 of the fine sand satisfies 0.15mm < D2 ≤ 0.3mm; The length of the short - cut polyvinyl alcohol fibers is 8 - 12mm, and the length of the long polyvinyl alcohol fibers is 80 - 120mm; The cement solid phase material is filled between the upper fabric layer and the lower fabric layer, and the upper fabric layer and the lower fabric layer are connected by needle punching.

[0011] It should be further noted that the low - alkali sulphoaluminate cement has a strength grade of 42.5.

[0012] It should be further noted that the short - cut polyvinyl alcohol fibers and the long polyvinyl alcohol fibers are pretreated before use. The pretreatment method is to soak them in an aqueous solution containing 0.5wt% - 1.0wt% of silane coupling agent for modification for 10 - 30 min.

[0013] It should be further noted that the ratio of the mass of the cement solid phase material to the area of the lower fabric layer is 1.0×10 4 ~1.5×10 4 kg / m 2 .

[0014] It should be further noted that the upper fabric layer is a non - woven fabric, and the lower fabric layer includes a stacked biodegradable film and a non - woven fabric. The biodegradable film of the lower fabric layer is in contact with the cement solid phase material.

[0015] It should be further noted that the non - woven fabrics of the upper fabric layer and the lower fabric layer are biodegradable non - woven fabrics, such as bamboo pulp fiber non - woven fabric, wood pulp fiber non - woven fabric, PLA corn fiber non - woven fabric, etc.

[0016] It should be further noted that the unit area mass of the non - woven fabric is 120 - 150 g / m 2 .

[0017] It should be further noted that the color of the non - woven fabric is green.

[0018] In the second aspect, the present invention provides a preparation method of the above - mentioned slope - protection cement blanket, which includes the following steps: (1) Divide each of the cement solid phase materials, except for polyvinyl alcohol long fibers, into two groups according to the weight proportions. Take one group of the materials after they are divided into equal parts and mix them evenly to obtain cement raw material one; then take the other group of the materials after they are divided into equal parts and mix them evenly to obtain cement raw material two. (2) Spread out the non-woven fabric and biodegradable membrane of the lower fabric layer evenly, spread cement raw material one evenly on the lower fabric layer, then spread polyvinyl alcohol long fiber, and then spread cement raw material two evenly on cement raw material one and polyvinyl alcohol long fiber. (3) Spread the non-woven fabric of the upper fabric layer evenly onto cement raw material 2, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

[0019] It should be further explained that step (4) is also included. When using it, the slope protection cement blanket is laid on the slope and water is sprayed onto the slope protection cement blanket to hydrate the raw materials of the cement solid phase material in the slope protection cement blanket.

[0020] It should be further noted that, based on the raw material mass of cement solids, the water spraying volume is 0.4~0.6 L / kg.

[0021] The beneficial effects of this invention are as follows: This invention selects low-alkali sulfur-alumina cement as the core cementitious material, providing basic mechanical strength for the cement solid phase material. The use of low-alkali cement also effectively avoids the adverse effects of excessively alkaline substrate on vegetation performance. Metakaolin is selected as an auxiliary cementitious material, further enhancing the material's later-stage strength and crack resistance. Coconut shell is used to regulate the internal microenvironment of the cement solid phase material; the coconut shell is embedded in the pores of the washed sand, preventing pore collapse due to cement shrinkage, and its naturally loose structure further increases gas exchange channels. Washed sand with a three-particle size blend is used; the coarse particles serve as the skeletal support structure, while the medium and fine particles fill the gaps, allowing the cement slurry to evenly coat each sand grain. The material is granular, forming a dense and mechanically stable whole, while retaining reasonable gaps to allow space for plant root growth; modified asphalt is used to improve the flexibility of the cement solid phase material, enhance its adaptability to minor slope deformations, and prevent cracking due to excessive rigidity; sodium carboxymethyl cellulose is used to reduce excessive water evaporation, ensure full cement hydration, and improve the adhesion between components, ensuring a uniform structure after molding; two lengths of polyvinyl alcohol fiber are used, with short-cut polyvinyl alcohol fiber enhancing the material's crack resistance and synergistically improving tensile strength with other components; and water-retaining resin is used to significantly improve the water retention capacity of the cement solid phase material. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0023] In the first aspect, the present invention provides a slope protection cement blanket, which achieves the synergy of flexible laying construction, mechanical stability and vegetation adaptability by rationally designing the composition ratio, particle size distribution and interlayer connection structure of cement solid phase material, thus solving the defects of traditional rigid slope protection in poor adaptability to complex slope terrain and weak vegetation performance.

[0024] The main component of the slope protection cement blanket is cement solid material; by weight, the raw materials of the cement solid material include: Low-alkali sulfur-alumina cement 25-35 parts, metakaolin 5-10 parts, coconut coir 10-18 parts, washed sand 25-40 parts, modified asphalt 3-8 parts, sodium carboxymethyl cellulose 0.5-2 parts, polyvinyl alcohol chopped short fiber 0.5-2 parts, polyvinyl alcohol long fiber 0.5-2 parts, water-retaining resin 5-10 parts.

[0025] The above-mentioned raw materials were designed after fully considering the mechanical and vegetation properties of the slope protection cement blanket. Utilizing low-alkali sulfur-aluminum cement avoids the inhibition of seed germination and root development caused by traditional high-alkali cement, thus meeting the needs of vegetation. Simultaneously, the introduction of metakaolin utilizes the activity of volcanic ash to undergo a secondary reaction with the free Ca(OH)2 generated during cement hydration, producing more CASH gel. This significantly improves the later-stage compressive strength and crack resistance of the cement solid material, strengthening mechanical support. Furthermore, it further consumes free alkali, synergistically optimizing the vegetation microenvironment with the low-alkali sulfur-aluminum cement.

[0026] As a preferred embodiment, the low-alkali sulfur-alumina cement is selected with a strength grade of 42.5. The use of fast-strength cement ensures that the cement blanket for slope protection can quickly complete hydration and solidification after water spraying, reducing material loss caused by rainwater erosion after construction and ensuring rapid formation of mechanical properties.

[0027] As a preferred specific embodiment, the washed sand is composed of coarse sand, medium sand and fine sand according to a mass ratio of 3:4:3. The particle size D1 of the coarse sand satisfies 0.6 mm < D1 ≤ 2.36 mm, the particle size D2 of the medium sand satisfies 0.3 mm < D2 ≤ 0.6 mm, and the particle size D2 of the fine sand satisfies 0.15 mm < D2 ≤ 0.3 mm. This continuous gradation design enables the washed sand to form a stacking structure with a coarse sand skeleton, medium sand filling, and fine sand leveling. The coarse sand provides a mechanical bearing foundation for the cement solid-phase material, avoiding compression deformation due to a weak skeleton after curing; the medium sand precisely fills the gaps between the coarse sand, reducing harmful pores inside the material and enhancing the overall density to improve the anti-scouring ability; the fine sand fills the tiny gaps between the medium sand, ensuring that the cement paste evenly wraps the surface of the aggregate and avoiding fluctuations in mechanical properties caused by uneven aggregate wrapping. At the same time, the effective pores reserved by this combination of washed sand happen to synergize with the fluffy structure of coconut soil and the water absorption characteristics of water-retaining resin, avoiding problems such as excessive density and poor air permeability or excessive looseness and low strength caused by a single aggregate gradation, and solving the balance problem between vegetation growth and mechanical properties.

[0028] As a preferred specific embodiment, the length of the polyvinyl alcohol short-cut fibers is 8 - 12 mm, and the length of the polyvinyl alcohol long fibers is 80 - 120 mm. The short-cut fibers can be evenly dispersed inside the cement solid-phase material, playing a role in suppressing microcracks during the cement hydration shrinkage process and ensuring the integrity of the micro-structure; the long fibers mainly play a role in enhancing the flexural strength of the cement blanket. In the present invention, the polyvinyl alcohol short-cut fibers are mixed with raw materials such as low-alkali sulfoaluminate cement and metakaolin, and the long fibers are spread between two layers of cement raw materials, without causing physical barriers to vegetation growth.

[0029] As a preferred specific embodiment, the polyvinyl alcohol short-cut fibers and the polyvinyl alcohol long fibers are pretreated before use. The pretreatment method is to soak them in an aqueous solution containing 0.5wt% - 1.0wt% silane coupling agent (KH-560) for modification for 10 - 30 min. The function of this pretreatment process is to form active groups containing hydroxyl and amino groups on the fiber surface through the coupling agent molecules, enhancing the interfacial bonding strength between the fiber and the cement hydration products and avoiding interfacial peeling between the fiber and the cement paste.

[0030] As a preferred specific embodiment, the cement solid-phase material is filled between the upper fabric layer and the lower fabric layer, and the upper fabric layer and the lower fabric layer are connected by needle punching.

[0031] As a preferred specific embodiment, the ratio of the mass of the cement solid-phase material to the area of the lower fabric layer is 1.0×10 4 ~1.5×10 4 kg / m 2This ensures that the cement blanket has sufficient thickness after curing, while avoiding difficulties in laying due to excessive thickness and weight of the material, thus balancing mechanical properties and ease of construction.

[0032] In a preferred embodiment, cement-based solid material is filled between an upper fabric layer and a lower fabric layer, which are connected by needle punching. The upper fabric layer is a non-woven fabric, and the lower fabric layer comprises a stacked biodegradable membrane and a non-woven fabric, with the biodegradable membrane of the lower fabric layer in contact with the cement-based solid material. The needle punching connection between the upper and lower fabric layers creates an integrated structure between the fabric layer and the cement-based solid material, preventing interlayer delamination after curing and enhancing overall mechanical stability. The non-woven fabric of the upper fabric layer has pores, allowing water to pass through smoothly during the hydration of the cement-based solid material. The lower fabric layer has a biodegradable membrane on its inner side, which intercepts water leakage from the non-woven fabric of the lower fabric layer during hydration, ensuring the hydration effect of the cement-based solid material.

[0033] In a preferred embodiment, the nonwoven fabrics of the upper and lower fabric layers are biodegradable nonwoven fabrics, such as bamboo pulp fiber nonwoven fabric, wood pulp fiber nonwoven fabric, PLA corn fiber nonwoven fabric, etc. Using biodegradable nonwoven fabrics allows the fabric to gradually degrade after the root system has matured, effectively avoiding long-term residue that hinders plant root growth and does not affect the integration of vegetation with the slope soil.

[0034] As a preferred embodiment, the nonwoven fabric has a unit area mass of 120~150 g / m². 2 .

[0035] As a preferred implementation method, green nonwoven fabric is used, which can blend into the surrounding environment in the early stages of construction and reduce visual abruptness.

[0036] Secondly, the present invention also provides a method for preparing the above-mentioned slope protection cement blanket, comprising the following steps: (1) All raw materials of cement solid material except polyvinyl alcohol long fiber (low alkali sulfur aluminum cement, metakaolin, coconut coir, washed sand, modified asphalt, sodium carboxymethyl cellulose, polyvinyl alcohol short chopped fiber, water-retaining resin) are divided into two groups according to the weight parts. The group after the raw materials are divided is mixed evenly to obtain cement raw material one; the other group after the raw materials are divided is mixed evenly to obtain cement raw material two.

[0037] (2) Spread out the non-woven fabric and biodegradable membrane of the lower fabric layer evenly, spread cement raw material one evenly on the lower fabric layer, then spread polyvinyl alcohol long fiber, and then spread cement raw material two evenly on cement raw material one and polyvinyl alcohol long fiber.

[0038] The present invention lays out polyvinyl alcohol long fibers separately without mixing them with other raw materials. This is because the long fibers are 80-120 mm in length, and if they are stirred with short fibers, aggregates, etc., they are prone to entanglement and agglomeration, resulting in uneven fiber dispersion. The subsequent laying out makes it easier to achieve uniform distribution of long fibers between the raw material layers, forming a synergistic reinforcement system with the polyvinyl alcohol short chopped fibers, which has microscopic crack resistance and macroscopic tensile strength.

[0039] (3) Spread the non-woven fabric of the upper fabric layer evenly onto cement raw material 2, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

[0040] Through needle punching, the nonwoven fabric of the upper and lower fabric layers binds the raw materials of the cement solid phase material between the two fabric layers, preventing leakage of the raw materials during the laying process.

[0041] As a preferred embodiment, the above preparation method further includes step (4): when in use, the slope protection cement blanket is laid on the slope, and water is sprayed onto the slope protection cement blanket to hydrate the raw materials of the cement solid phase material in the slope protection cement blanket. This hydration method greatly simplifies the construction process, reduces the construction difficulty of complex slope terrain, and demonstrates the advantages of flexible construction of slope protection cement blanket.

[0042] As a preferred embodiment, the water spraying volume is 0.4~0.6 L / kg based on the raw material mass of the cement solid material. This water spraying volume is determined based on the synergistic function of cement hydration and water-retaining resin, which can ensure that the cement particles are fully hydrated, guarantee mechanical strength, and prevent excessive moisture from causing excessive porosity in the raw material; at the same time, the water-retaining resin can absorb some moisture, store it in the pores of the raw material, and release it slowly.

[0043] Example 1 A type of slope protection cement blanket, the main body of which is a cement solid material, filled between an upper fabric layer and a lower fabric layer. The upper fabric layer is a green PLA corn fiber nonwoven fabric (120 g / m²). 2 The lower fabric layer consists of stacked biodegradable membranes and green PLA corn fiber nonwoven fabric (120 g / m²). 2 The biodegradable membrane of the lower fabric layer is in contact with the cement solid phase material, and the upper and lower fabric layers are connected by needle punching.

[0044] The raw materials for cement solid phase materials, by weight, include: 25 parts of low-alkali sulfur-aluminum cement (grade 42.5), 10 parts of metakaolin, 10 parts of coconut coir, 40 parts of washed sand, 8 parts of modified asphalt, 0.5 parts of sodium carboxymethyl cellulose, 1 part of polyvinyl alcohol chopped short fiber, 0.5 parts of polyvinyl alcohol long fiber, and 5 parts of water-retaining resin.

[0045] Among them, the low-alkali sulphoaluminate cement (grade 42.5) was purchased from Tangshan Polar Bear Building Materials Co., Ltd.

[0046] The metakaolin was purchased from Langfang Shuangma Chemical Industry Co., Ltd.

[0047] The coconut soil was purchased from Zhuoye Mineral Products Processing Factory in Lingshou County.

[0048] The washed sand is composed of coarse sand, medium sand and fine sand according to the mass ratio of 3:4:3. The particle size D1 of the coarse sand satisfies 0.6 mm < D1 ≤ 2.36 mm, the particle size D2 of the medium sand satisfies 0.3 mm < D2 ≤ 0.6 mm, and the particle size D2 of the fine sand satisfies 0.15 mm < D2 ≤ 0.3 mm.

[0049] The modified asphalt is SBS modified emulsified asphalt and was purchased from Qilu Petrochemical Company, Sinopec.

[0050] The sodium carboxymethyl cellulose was purchased from Zibo Daoqin New Materials Co., Ltd.

[0051] The length of the polyvinyl alcohol short cut fiber is 8 mm, and the length of the polyvinyl alcohol long fiber is 120 mm. Both were purchased from Taian Songze Composite Materials Co., Ltd., and the fiber diameter is 15 μm ± 3 μm; the polyvinyl alcohol short cut fiber and the polyvinyl alcohol long fiber are pretreated before use. The pretreatment method is to soak and modify in an aqueous solution containing 1.0 wt% silane coupling agent (KH-550) for 10 min.

[0052] The water retention resin is potassium polyacrylate and was purchased from Renqiu Hengyu Chemical Industry Co., Ltd.

[0053] The ratio of the mass of the cement solid phase material to the area of the lower fabric layer is 1.0×10 4 kg / m 2 .

[0054] The preparation method of the slope protection cement blanket includes the following steps: (1) Take 12.5 parts of low-alkali sulphoaluminate cement, 5 parts of metakaolin, 5 parts of coconut soil, 20 parts of washed sand, 4 parts of modified asphalt, 0.25 part of sodium carboxymethyl cellulose, 0.5 part of polyvinyl alcohol short cut fiber, and 2.5 parts of water retention resin, mix them evenly to obtain the first cement raw material; then take 12.5 parts of low-alkali sulphoaluminate cement, 5 parts of metakaolin, 5 parts of coconut soil, 20 parts of washed sand, 4 parts of modified asphalt, 0.25 part of sodium carboxymethyl cellulose, 0.5 part of polyvinyl alcohol short cut fiber, and 2.5 parts of water retention resin, mix them evenly to obtain the second cement raw material.

[0055] (2) Evenly spread out the PLA corn fiber non-woven fabric and the biodegradable film of the lower fabric layer, evenly spread out the first cement raw material onto the lower fabric layer, then sprinkle 0.5 parts of polyvinyl alcohol long fibers, and then evenly spread out the second cement raw material onto the first cement raw material and the polyvinyl alcohol long fibers.

[0056] (3) Evenly spread out the PLA corn fiber non-woven fabric of the upper fabric layer onto the second cement raw material, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

[0057] (4) When in use, lay the slope protection cement blanket on the slope, spray water onto the slope protection cement blanket. Calculated based on the raw material mass of the cement solid phase material, the water spray amount is 0.4 L / kg, so that the raw materials of the cement solid phase material in the slope protection cement blanket undergo hydration.

[0058] Example 2 A slope protection cement blanket, the main body of the slope protection cement blanket is a cement solid phase material, and the cement solid phase material is filled between the upper fabric layer and the lower fabric layer. The upper fabric layer is a green PLA corn fiber non-woven fabric (150 g / m 2 ), and the lower fabric layer includes a stacked biodegradable film and a green PLA corn fiber non-woven fabric (150 g / m 2 ). The biodegradable film of the lower fabric layer contacts the cement solid phase material, and the upper fabric layer and the lower fabric layer are connected by needle punching.

[0059] Calculated by weight parts, the raw materials of the cement solid phase material include: 35 parts of low-alkali sulphoaluminate cement (42.5 grade), 5 parts of metakaolin, 18 parts of coconut soil, 25 parts of washed sand, 3 parts of modified asphalt, 2 parts of sodium carboxymethyl cellulose, 2 parts of polyvinyl alcohol short fibers, 2 parts of polyvinyl alcohol long fibers, 8 parts of water retention resin.

[0060] Among them, the low-alkali sulphoaluminate cement (42.5 grade) is purchased from Tangshan Polar Bear Building Materials Co., Ltd.

[0061] The metakaolin is purchased from Langfang Shuangma Chemical Industry Co., Ltd.

[0062] The coconut soil is purchased from Zhuoye Mineral Products Processing Factory in Lingshou County.

[0063] The washed sand is composed of coarse sand, medium sand and fine sand according to a mass ratio of 3:4:3. The particle size D1 of the coarse sand satisfies 0.6 mm < D1 ≤ 2.36 mm, the particle size D2 of the medium sand satisfies 0.3 mm < D2 ≤ 0.6 mm, and the particle size D2 of the fine sand satisfies 0.15 mm < D2 ≤ 0.3 mm.

[0064] The modified asphalt is SBS modified emulsified asphalt, purchased from Qilu Petrochemical Company, Sinopec.

[0065] Sodium carboxymethyl cellulose was purchased from Zibo Daoqin New Materials Co., Ltd.

[0066] The length of the polyvinyl alcohol chopped short fibers was 12 mm, and the length of the polyvinyl alcohol long fibers was 80 mm. Both were purchased from Taian Songze Composite Materials Co., Ltd., and the fiber diameter was 15 μm ± 3 μm. The polyvinyl alcohol chopped short fibers and polyvinyl alcohol long fibers were pretreated before use. The pretreatment method was to soak them in an aqueous solution containing 0.5 wt% silane coupling agent (KH-550) for 30 min for modification.

[0067] The water-retaining resin is potassium polyacrylate, purchased from Renqiu Hengyu Chemical Co., Ltd.

[0068] The ratio of the mass of the cement solid material to the area of ​​the underlying fabric layer is 1.5 × 10⁻⁶. 4 kg / m 2 .

[0069] The preparation method of this slope protection cement blanket includes the following steps: (1) Take 17.5 parts of low-alkali sulfur-alumina cement, 2.5 parts of metakaolin, 9 parts of coconut coir, 12.5 parts of washed sand, 1.5 parts of modified asphalt, 1 part of sodium carboxymethyl cellulose, 1 part of polyvinyl alcohol chopped fiber, and 4 parts of water-retaining resin and mix them evenly to obtain cement raw material one; then take 17.5 parts of low-alkali sulfur-alumina cement, 2.5 parts of metakaolin, 9 parts of coconut coir, 12.5 parts of washed sand, 1.5 parts of modified asphalt, 1 part of sodium carboxymethyl cellulose, 1 part of polyvinyl alcohol chopped fiber, and 4 parts of water-retaining resin and mix them evenly to obtain cement raw material two.

[0070] (2) Spread out the PLA corn fiber nonwoven fabric and biodegradable membrane in the lower fabric layer evenly, spread cement raw material one evenly on the lower fabric layer, then spread 2 parts of polyvinyl alcohol long fiber, and then spread cement raw material two evenly on cement raw material one and polyvinyl alcohol long fiber.

[0071] (3) Spread the PLA corn fiber nonwoven fabric of the upper fabric layer evenly on the cement raw material 2, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

[0072] (4) When using, lay the slope protection cement blanket on the slope and spray it. The amount of water sprayed is 0.6 L / kg based on the raw material mass of the cement solid material, so that the raw material of the cement solid material in the slope protection cement blanket will be hydrated.

[0073] Example 3 A type of slope protection cement blanket, the main body of which is a cement solid material, filled between an upper fabric layer and a lower fabric layer. The upper fabric layer is a green PLA corn fiber nonwoven fabric (120 g / m²). 2), the lower fabric layer includes a stacked biodegradable film and a green PLA corn fiber non-woven fabric (120 g / m 2 ), the biodegradable film of the lower fabric layer contacts the cement solid phase material, and the upper fabric layer and the lower fabric layer are connected by needle punching.

[0074] By weight, the raw materials of the cement solid phase material include: 30 parts of low-alkali sulphoaluminate cement (grade 42.5), 8 parts of metakaolin, 13 parts of coconut soil, 35 parts of washed sand, 5 parts of modified asphalt, 1 part of sodium carboxymethyl cellulose, 1 part of polyvinyl alcohol short fiber, 1 part of polyvinyl alcohol long fiber, and 6 parts of water retention resin.

[0075] Among them, the low-alkali sulphoaluminate cement (grade 42.5) is purchased from Tangshan Polar Bear Building Materials Co., Ltd.

[0076] The metakaolin is purchased from Langfang Shuangma Chemical Co., Ltd.

[0077] The coconut soil is purchased from Zhuoye Mineral Products Processing Factory, Lingshou County.

[0078] The washed sand is composed of coarse sand, medium sand and fine sand according to a mass ratio of 3:4:3. The particle size D1 of the coarse sand satisfies 0.6 mm < D1 ≤ 2.36 mm, the particle size D2 of the medium sand satisfies 0.3 mm < D2 ≤ 0.6 mm, and the particle size D2 of the fine sand satisfies 0.15 mm < D2 ≤ 0.3 mm.

[0079] The modified asphalt is SBS modified emulsified asphalt and is purchased from Qilu Petrochemical Company, Sinopec.

[0080] The sodium carboxymethyl cellulose is purchased from Zibo Daoqin New Materials Co., Ltd.

[0081] The length of the polyvinyl alcohol short fiber is 10 mm, and the length of the polyvinyl alcohol long fiber is 100 mm. Both are purchased from Taian Songze Composite Materials Co., Ltd., and the fiber diameter is 15 μm ± 3 μm; the polyvinyl alcohol short fiber and the polyvinyl alcohol long fiber are pretreated before use. The pretreatment method is to soak in an aqueous solution containing 1 wt% silane coupling agent (KH-550) for 15 minutes for modification.

[0082] The water retention resin is potassium polyacrylate and is purchased from Renqiu Hengyu Chemical Co., Ltd.

[0083] The ratio of the mass of the cement solid phase material to the area of the lower fabric layer is 1.2×10 4 kg / m 2 .

[0084] The preparation method of this slope protection cement blanket includes the following steps: (1) Take 15 parts of low-alkali sulfur-alumina cement, 4 parts of metakaolin, 6.5 parts of coconut coir, 17.5 parts of washed sand, 2.5 parts of modified asphalt, 0.5 parts of sodium carboxymethyl cellulose, 0.5 parts of polyvinyl alcohol chopped fiber, and 3 parts of water-retaining resin and mix them evenly to obtain cement raw material one; then take 15 parts of low-alkali sulfur-alumina cement, 4 parts of metakaolin, 6.5 parts of coconut coir, 17.5 parts of washed sand, 2.5 parts of modified asphalt, 0.5 parts of sodium carboxymethyl cellulose, 0.5 parts of polyvinyl alcohol chopped fiber, and 3 parts of water-retaining resin and mix them evenly to obtain cement raw material two.

[0085] (2) Spread out the PLA corn fiber nonwoven fabric and biodegradable membrane in the lower fabric layer evenly, spread cement raw material one evenly on the lower fabric layer, then spread 1 part of polyvinyl alcohol long fiber, and then spread cement raw material two evenly on cement raw material one and polyvinyl alcohol long fiber.

[0086] (3) Spread the PLA corn fiber nonwoven fabric of the upper fabric layer evenly on the cement raw material 2, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

[0087] (4) When using, lay the slope protection cement blanket on the slope and spray it. The amount of water sprayed is 0.5 L / kg based on the raw material mass of the cement solid material, so that the raw material of the cement solid material in the slope protection cement blanket will be hydrated.

[0088] Comparative Example 1 A type of slope protection cement blanket, the main body of which is a cement solid material, filled between an upper fabric layer and a lower fabric layer. The upper fabric layer is a green PLA corn fiber nonwoven fabric (120 g / m²). 2 The lower fabric layer consists of stacked biodegradable membranes and green PLA corn fiber nonwoven fabric (120 g / m²). 2 The biodegradable membrane of the lower fabric layer is in contact with the cement solid phase material, and the upper and lower fabric layers are connected by needle punching.

[0089] The raw materials for cement solid phase materials, by weight, include: 30 parts of low-alkali sulfur-aluminum cement (grade 42.5), 8 parts of metakaolin, 13 parts of coconut coir, 35 parts of washed sand, 5 parts of modified asphalt, 1 part of sodium carboxymethyl cellulose, 1 part of polyvinyl alcohol chopped short fiber, 1 part of polyvinyl alcohol long fiber, and 6 parts of water-retaining resin.

[0090] The low-alkali sulfur-alumina cement (grade 42.5) was purchased from Tangshan Arctic Bear Building Materials Co., Ltd.

[0091] The metakaolin was purchased from Langfang Shuangma Chemical Co., Ltd.

[0092] The coconut clay was purchased from Zhuoye Mineral Products Processing Plant in Lingshou County.

[0093] The washed sand is composed of coarse sand, medium sand and fine sand in a mass ratio of 3:4:3. The particle size D1 of the coarse sand satisfies 0.6 mm < D1 ≤ 2.36 mm, the particle size D2 of the medium sand satisfies 0.3 mm < D2 ≤ 0.6 mm, and the particle size D2 of the fine sand satisfies 0.15 mm < D2 ≤ 0.3 mm.

[0094] The modified asphalt is SBS modified emulsified asphalt, purchased from Qilu Petrochemical Company, Sinopec.

[0095] Sodium carboxymethyl cellulose is purchased from Zibo Daoqin New Materials Co., Ltd.

[0096] The length of the polyvinyl alcohol chopped fiber is 10 mm, and the length of the polyvinyl alcohol long fiber is 100 mm. Both are purchased from Taian Songze Composite Materials Co., Ltd., and the fiber diameter is 15 μm ± 3 μm. The polyvinyl alcohol chopped fiber and the polyvinyl alcohol long fiber are pretreated before use. The pretreatment method is to soak in an aqueous solution containing 1 wt% silane coupling agent (KH-550) for 15 minutes for modification.

[0097] The water retention resin is potassium polyacrylate, purchased from Renqiu Hengyu Chemical Co., Ltd.

[0098] The ratio of the mass of the cement solid material to the area of the lower fabric layer is 1.2×10 4 kg / m 2 .

[0099] The preparation method of the slope protection cement blanket includes the following steps: (1) Take 30 parts of low-alkali sulphoaluminate cement (grade 42.5), 8 parts of metakaolin, 13 parts of coconut soil, 35 parts of washed sand, 5 parts of modified asphalt, 1 part of sodium carboxymethyl cellulose, 1 part of polyvinyl alcohol chopped fiber, 1 part of polyvinyl alcohol long fiber, and 6 parts of water retention resin, and mix them evenly to obtain a cement raw material.

[0100] (2) Spread the PLA corn fiber non-woven fabric and the biodegradable film of the lower fabric layer evenly, and spread the cement raw material evenly on the lower fabric layer.

[0101] (3) Spread the PLA corn fiber non-woven fabric of the upper fabric layer evenly on the cement raw material, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

[0102] (4) During use, lay the slope protection cement blanket on the slope, and spray water on the slope protection cement blanket. Calculated by the raw material mass of the cement solid material, the water spraying amount is 0.5 L / kg, so that the raw materials of the cement solid material in the slope protection cement blanket undergo hydration.

[0103] Comparative Example 2 A slope protection cement blanket, the main body of the slope protection cement blanket is a cement solid phase material, and the cement solid phase material is filled between the upper fabric layer and the lower fabric layer. The upper fabric layer is a green PLA corn fiber non-woven fabric (120 g / m 2 ), the lower fabric layer includes a stacked biodegradable film and a green PLA corn fiber non-woven fabric (120 g / m 2 ), the biodegradable film of the lower fabric layer contacts the cement solid phase material, and the upper fabric layer and the lower fabric layer are connected by needle punching.

[0104] By weight, the raw materials of the cement solid phase material include: 30 parts of low-alkali sulphoaluminate cement (grade 42.5), 8 parts of metakaolin, 13 parts of coconut soil, 35 parts of washed sand, 5 parts of modified asphalt, 1 part of sodium carboxymethyl cellulose, 1 part of polyvinyl alcohol short cut fiber, 1 part of polyvinyl alcohol long fiber, and 6 parts of water retention resin.

[0105] Among them, the low-alkali sulphoaluminate cement (grade 42.5) is purchased from Tangshan Polar Bear Building Materials Co., Ltd.

[0106] The metakaolin is purchased from Langfang Shuangma Chemical Industry Co., Ltd.

[0107] The coconut soil is purchased from Zhuoye Mineral Products Processing Factory in Lingshou County.

[0108] The washed sand is composed of coarse sand, medium sand and fine sand according to the mass ratio of 3:4:5. The particle size D1 of the coarse sand satisfies 0.6 mm < D1 ≤ 2.36 mm, the particle size D2 of the medium sand satisfies 0.3 mm < D2 ≤ 0.6 mm, and the particle size D2 of the fine sand satisfies 0.15 mm < D2 ≤ 0.3 mm.

[0109] The modified asphalt is SBS modified emulsified asphalt and is purchased from Qilu Petrochemical Company of Sinopec.

[0110] The sodium carboxymethyl cellulose is purchased from Zibo Daoqin New Materials Co., Ltd.

[0111] The length of the polyvinyl alcohol short cut fiber is 10 mm, and the length of the polyvinyl alcohol long fiber is 100 mm. Both are purchased from Tai'an Songze Composite Materials Co., Ltd., and the fiber diameter is 15 μm ± 3 μm; the polyvinyl alcohol short cut fiber and the polyvinyl alcohol long fiber are pretreated before use. The pretreatment method is to soak in an aqueous solution containing 1 wt% silane coupling agent (KH-550) for modification for 15 min.

[0112] The water retention resin is potassium polyacrylate and is purchased from Renqiu Hengyu Chemical Industry Co., Ltd.

[0113] The ratio of the mass of the cement solid phase material to the area of the lower fabric layer is 1.2×10 4 kg / m 2 .

[0114] The preparation method of this slope protection cement blanket includes the following steps: (1) Take 15 parts of low-alkali sulfur-alumina cement, 4 parts of metakaolin, 6.5 parts of coconut coir, 17.5 parts of washed sand, 2.5 parts of modified asphalt, 0.5 parts of sodium carboxymethyl cellulose, 0.5 parts of polyvinyl alcohol chopped fiber, and 3 parts of water-retaining resin and mix them evenly to obtain cement raw material one; then take 15 parts of low-alkali sulfur-alumina cement, 4 parts of metakaolin, 6.5 parts of coconut coir, 17.5 parts of washed sand, 2.5 parts of modified asphalt, 0.5 parts of sodium carboxymethyl cellulose, 0.5 parts of polyvinyl alcohol chopped fiber, and 3 parts of water-retaining resin and mix them evenly to obtain cement raw material two.

[0115] (2) Spread out the PLA corn fiber nonwoven fabric and biodegradable membrane in the lower fabric layer evenly, spread cement raw material one evenly on the lower fabric layer, then spread 1 part of polyvinyl alcohol long fiber, and then spread cement raw material two evenly on cement raw material one and polyvinyl alcohol long fiber.

[0116] (3) Spread the PLA corn fiber nonwoven fabric of the upper fabric layer evenly on the cement raw material 2, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

[0117] (4) When using, lay the slope protection cement blanket on the slope and spray it. The amount of water sprayed is 0.5 L / kg based on the raw material mass of the cement solid material, so that the raw material of the cement solid material in the slope protection cement blanket will be hydrated.

[0118] Comparative Example 3 A type of slope protection cement blanket, the main body of which is a cement solid material, filled between an upper fabric layer and a lower fabric layer. The upper fabric layer is a green PLA corn fiber nonwoven fabric (120 g / m²). 2 The lower fabric layer consists of stacked biodegradable membranes and green PLA corn fiber nonwoven fabric (120 g / m²). 2 The biodegradable membrane of the lower fabric layer is in contact with the cement solid phase material, and the upper and lower fabric layers are connected by needle punching.

[0119] The raw materials for cement solid phase materials, by weight, include: 36 parts of low-alkali sulfur-alumina cement (grade 42.5), 8 parts of metakaolin, 42 parts of washed sand, 5 parts of modified asphalt, 1 part of sodium carboxymethyl cellulose, 1 part of polyvinyl alcohol chopped short fiber, 1 part of polyvinyl alcohol long fiber, and 6 parts of water-retaining resin.

[0120] The low-alkali sulfur-alumina cement (grade 42.5) was purchased from Tangshan Arctic Bear Building Materials Co., Ltd.

[0121] The metakaolin was purchased from Langfang Shuangma Chemical Co., Ltd.

[0122] The washed sand is composed of coarse sand, medium sand and fine sand in a mass ratio of 3:4:3. The particle size D1 of the coarse sand satisfies 0.6 mm < D1 ≤ 2.36 mm, the particle size D2 of the medium sand satisfies 0.3 mm < D2 ≤ 0.6 mm, and the particle size D2 of the fine sand satisfies 0.15 mm < D2 ≤ 0.3 mm.

[0123] The modified asphalt is SBS modified emulsified asphalt, purchased from Qilu Petrochemical Company, Sinopec.

[0124] Sodium carboxymethyl cellulose is purchased from Zibo Daoqin New Materials Co., Ltd.

[0125] The length of the polyvinyl alcohol short cut fibers is 10 mm, and the length of the polyvinyl alcohol long fibers is 100 mm. Both are purchased from Tai'an Songze Composite Materials Co., Ltd., and the fiber diameter is 15 μm ± 3 μm; the polyvinyl alcohol short cut fibers and the polyvinyl alcohol long fibers are pretreated before use. The pretreatment method is to soak them in an aqueous solution containing 1 wt% silane coupling agent (KH-550) for 15 minutes for modification.

[0126] The water retention resin is potassium polyacrylate, purchased from Renqiu City Hengyu Chemical Co., Ltd.

[0127] The ratio of the mass of the cement solid material to the area of the lower fabric layer is 1.2×10 4 kg / m 2 .

[0128] The preparation method of the slope protection cement blanket includes the following steps: (1) Take 18 parts of low-alkali sulphoaluminate cement, 4 parts of metakaolin, 21 parts of washed sand, 2.5 parts of modified asphalt, 0.5 parts of sodium carboxymethyl cellulose, 0.5 parts of polyvinyl alcohol short cut fibers, and 3 parts of water retention resin and mix them evenly to obtain the first cement raw material; then take 18 parts of low-alkali sulphoaluminate cement, 4 parts of metakaolin, 21 parts of washed sand, 2.5 parts of modified asphalt, 0.5 parts of sodium carboxymethyl cellulose, 0.5 parts of polyvinyl alcohol short cut fibers, and 3 parts of water retention resin and mix them evenly to obtain the second cement raw material.

[0129] (2) Spread the PLA corn fiber non-woven fabric and the biodegradable film of the lower fabric layer evenly, spread the first cement raw material evenly on the lower fabric layer, then sprinkle 1 part of polyvinyl alcohol long fibers, and then spread the second cement raw material evenly on the first cement raw material and the polyvinyl alcohol long fibers.

[0130] (3) Spread the PLA corn fiber non-woven fabric of the upper fabric layer evenly on the second cement raw material, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

[0131] (4) When using, lay the slope protection cement blanket on the slope and spray it. The amount of water sprayed is 0.5 L / kg based on the raw material mass of the cement solid material, so that the raw material of the cement solid material in the slope protection cement blanket will be hydrated.

[0132] Test Example 1 The unhydrated slope protection cement blankets obtained in step (3) of Examples 1-3 and Comparative Examples 1-3 were used as test objects. They were hydrated with the appropriate amount of water and their setting time was tested. The test method was based on GB / T 1346 "Test Method for Standard Consistency Water Quantity, Setting Time and Soundness of Cement". The results showed that each slope protection cement blanket could complete the final setting within 30 minutes.

[0133] Referring to GB / T 17671-2021 "Test Method for Strength of Cement Mortar", the cement solid material raw materials (excluding polyvinyl alcohol long fibers) from Examples 1-3 and Comparative Examples 2-3 were mixed with 0.5 L / kg of water to obtain mortar. The mortar was then molded to obtain prisms of 40 mm × 40 mm × 160 mm. During molding, the mortar was placed in two layers into the mold; after the first layer was placed, polyvinyl alcohol long fibers were spread on the surface, and then the second layer of mortar was added. Similarly, all the cement solid material raw materials from Comparative Example 1 were mixed with 0.5 L / kg of water to obtain mortar, which was then molded to obtain prisms of 40 mm × 40 mm × 160 mm. During molding, the mortar was placed in two layers into the mold; after the first layer was placed, the second layer of mortar was added.

[0134] The specimens from each embodiment and comparative example were cured in water at 20℃±1℃. The flexural strength and compressive strength of the specimens were then tested at 24 h and 7 d. The test results are shown in Table 1 below.

[0135] Table 1. Flexural and compressive strength results of specimens from each example and comparative example.

[0136] As can be seen from the test results in Table 1, compared with the specimens prepared using the cement solid material raw materials or methods of the comparative examples, the specimens prepared using the cement solid material raw materials or methods of this invention showed better performance in terms of compressive strength and flexural strength. In Comparative Example 1, all raw materials were directly mixed, causing the polyvinyl alcohol long fibers to entangle and agglomerate during stirring, making uniform dispersion impossible and weakening the overall strength. In Comparative Example 2, the excessive fine sand slightly improved the density, but the overall flexural and compressive strength decreased. In Comparative Example 3, no coconut coir was used. Although the low-alkali sulfur-alumina cement was increased to 36 parts and the washed sand to 42 parts to compensate for the component deficiency, the fibrous structure of coconut coir could help disperse cement particles and fibers, and its uniform dispersion characteristics ensured the consistency of the hydration reaction. Without coconut coir, cement particles were prone to local agglomeration, and the interfacial coordination between fibers and cement paste decreased. Although the cement content was increased, the overall synergy was weaker than in Example 3.

[0137] Test Example 2 The vegetation performance of the slope protection cement blanket was tested using a slope simulation device. The slope simulation device was adjusted to a slope angle of 30°. First, a 10 cm thick layer of soil was laid. The soil formula included 70 wt% greening planting soil, 20 wt% red clay, 3 wt% vermiculite, 2 wt% expanded clay, 0.5 wt% ferric sulfate, 0.5 wt% organic fertilizer, 1 wt% fly ash, and 3 wt% EVA emulsion. The fly ash and EVA emulsion in the soil formula could play a role in soil stabilization, ensuring that the soil would not be seriously lost during the experiment. Then, the slope protection cement blanket (40 cm long and 20 cm wide) of Example 1-3 and Comparative Example 1-3 (3) was laid on the slope simulation device and fixed with a nail gun. It was hydrated with the appropriate amount of water and cured at 20℃±1℃ for 28 days. After curing, a 6 cm thick layer of soil was laid on the slope protection cement blanket.

[0138] The pre-soaked ryegrass seeds were then buried in the soil, covered with a thin layer of soil, and gently pressed flat. 150 ryegrass seeds were planted on each section of the cement slab used for slope protection. The experimental environment was controlled at a constant temperature of 25℃, with natural light, and the soil moisture content was maintained at 40%-60%. Germination was observed daily after sowing. In both the example and comparative studies, the ryegrass mainly germinated on days 4-5. The height of 30 ryegrass plants was randomly measured and recorded on days 15, 30, 45, and 60. The results are shown in Table 2 below.

[0139] Table 2. Ryegrass growth on the cement blankets used for slope protection in each embodiment and comparative example.

[0140] After 60 days of the experiment, ryegrass planted on the cement blankets of the various embodiments and comparative examples was randomly selected. The surrounding soil was carefully cleared, taking care not to damage the ryegrass roots. The roots were observed, revealing that the ryegrass planted on the cement blankets of the embodiments exhibited strong penetration, numerous branches, and long roots. The average root length of the three embodiments was 18.5–21.5 cm, and the roots were thicker, forming a good bond with the cement blanket and the underlying soil. The ryegrass planted on the cement blankets of the comparative examples showed shorter roots, fewer branches, and localized fiber entanglement. Specifically, Comparative Example 2 had a high fine sand content, and Comparative Example 3's cement solid material lacked coconut coir. Therefore, the cement solid materials in both comparative examples had limited space for root growth, resulting in poor root penetration.

[0141] The results above show that the ryegrass planted on the slope protection cement blanket in this embodiment of the invention has a better overall growth compared to the control group, indicating that the slope protection cement blanket provided by this invention has a reasonable and superior design in terms of vegetation adaptability.

[0142] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A slope protection cement blanket, characterized in that, The main body of the slope protection cement blanket is a cement solid-phase material; calculated by weight parts, the raw materials of the cement solid-phase material include: 25-35 parts of low-alkali sulphoaluminate cement, 5-10 parts of metakaolin, 10-18 parts of coconut soil, 25-40 parts of washed sand, 3-8 parts of modified asphalt, 0.5-2 parts of sodium carboxymethyl cellulose, 0.5-2 parts of polyvinyl alcohol short fibers, 0.5-2 parts of polyvinyl alcohol long fibers, 5-10 parts of water retention resin. Among them, the washed sand is composed of coarse sand, medium sand and fine sand according to the mass ratio of 3:4:

3. The particle size D1 of the coarse sand satisfies 0.6 mm < D1 ≤ 2.36 mm, the particle size D2 of the medium sand satisfies 0.3 mm < D2 ≤ 0.6 mm, and the particle size D2 of the fine sand satisfies 0.15 mm < D2 ≤ 0.3 mm. The length of the polyvinyl alcohol short fibers is 8-12 mm, and the length of the polyvinyl alcohol long fibers is 80-120 mm. The cement solid-phase material is filled between the upper fabric layer and the lower fabric layer, and the upper fabric layer and the lower fabric layer are connected by needle punching.

2. The slope protection cement blanket as described in claim 1, characterized in that, The low-alkali sulphoaluminate cement is selected with a strength grade of 42.

5.

3. The slope protection cement blanket as described in claim 1, characterized in that, The polyvinyl alcohol short fibers and the polyvinyl alcohol long fibers are pretreated before use. The pretreatment method is to soak in an aqueous solution containing 0.5wt%-1.0wt% of silane coupling agent for 10-30 min for modification.

4. The slope protection cement blanket as described in claim 1, characterized in that, The ratio of the mass of the cement solid material to the area of ​​the underlying fabric layer is 1.0 × 10⁻⁶. 4 ~1.5×10 4 kg / m 2 .

5. The slope protection cement blanket as described in claim 1, characterized in that, The upper fabric layer is a non-woven fabric, and the lower fabric layer includes a stacked biodegradable film and a non-woven fabric. The biodegradable film of the lower fabric layer contacts the cement solid-phase material.

6. The slope protection cement blanket as described in claim 1, characterized in that, The non-woven fabrics of the upper fabric layer and the lower fabric layer are biodegradable non-woven fabrics.

7. The slope protection cement blanket as described in claim 1, characterized in that, The unit area mass of nonwoven fabric is 120~150g / m². 2 .

8. A method for preparing a slope protection cement blanket as described in any one of claims 1-7, characterized in that, It includes the following steps: (1) Divide each raw material of the cement solid-phase material except the polyvinyl alcohol long fibers into two groups according to weight parts on average. Take one group after the average division of each raw material and mix them evenly to obtain the first cement raw material; then take the other group after the average division of each raw material and mix them evenly to obtain the second cement raw material. (2) Evenly spread out the non-woven fabric and the biodegradable film of the lower fabric layer, evenly spread the first cement raw material onto the lower fabric layer, then spread the polyvinyl alcohol long fibers, and then evenly spread the second cement raw material onto the first cement raw material and the polyvinyl alcohol long fibers. (3) Evenly spread out the non-woven fabric of the upper fabric layer onto the second cement raw material, and connect and fix the upper fabric layer and the lower fabric layer by needle punching.

9. The method for preparing the slope protection cement blanket as described in claim 8, characterized in that, It also includes step (4). During use, lay the slope protection cement blanket on the slope and spray water on the slope protection cement blanket to cause the raw materials of the cement solid-phase material in the slope protection cement blanket to hydrate.

10. The method for preparing the slope protection cement blanket as described in claim 9, characterized in that, Calculated by the mass of the raw materials of the cement solid-phase material, the water spraying amount is 0.4-0.6 L / kg.

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