Grouting material for reinforcing soft soil and soft rock slopes and preparation method of grouting material

Abstract

The invention provides a grouting material for reinforcing soft soil and soft rock slopes and a preparation method, and belongs to the technical field of civil engineering materials. The grouting material is prepared from the following raw materials: granulated blast furnace slag, steel slag, fly ash, silica fume, metakaolin, a compound alkali activator, nano silicon dioxide, reinforced fibers and an organic silicon water repellent. Multi-particle-size grading is used, full-range filling is achieved, a compact stacking structure is formed, silica fume and nano-silica cooperate with microcrystal nuclei in the steel slag, so that the pore connectivity is reduced, and the silica fume and the nano-silica cooperate with the organic silicon water repellent, so that the corrosion resistance of the material is improved; a composite gel network structure is formed, and the composite network structure not only can quickly form an early strength skeleton, but also can realize continuous increase of strength; a slurry-rock soil interface transition layer is formed, and the interface bonding strength is improved; by adding the reinforcing fibers, the strength and toughness of the grouting material are further improved, loads of soft soil and soft rock slopes can be effectively borne, and the requirement of slope reinforcement for strength is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of civil engineering materials, and particularly relates to a grouting material for soft soil and soft rock slope reinforcement and a preparation method thereof. Background Art

[0002] Soft soil (such as silt, clay) and soft rock (such as mudstone, shale) slopes widely exist in projects such as highways, railways, and water conservancy. They generally have problems such as low bearing capacity, weak shear strength, and susceptibility to environmental erosion. Under the influence of external factors such as rainwater infiltration, wet-dry cycles, and freeze-thaw actions, such slopes are prone to geological disasters such as landslides, collapses, and uneven settlements, seriously threatening engineering safety. Although traditional reinforcement means (such as anchor rods, soil nail walls) can stabilize the slope in the short term, due to the defects of material properties, their long-term durability and environmental adaptability are insufficient, and there is an urgent need to develop new high-performance grouting materials.

[0003] Currently, portland cement-based grouting materials are commonly used in engineering, but they have the following key defects in soft soil or soft rock reinforcement: Insufficient durability: Cement hydration products (such as Ca(OH)2, ettringite, etc.) are susceptible to Cl - , SO4 2- erosion, and the compressive strength attenuation rate exceeds 30% in 28 days in a humid environment, which easily leads to the failure of the anchor solid.

[0004] Weak interfacial bonding: The interface between the cement paste and soft soil or soft rock is mainly physical bonding, lacking chemical bonding. The interfacial shear strength is only 1.0 - 1.5 MPa (ASTM D4541), and peeling is likely to occur.

[0005] Risk of shrinkage cracking: The cement hydration shrinkage rate is as high as 0.05 - 0.10% (GB / T 50082 - 2009). Microcracks accelerate the penetration of erosion media and shorten the service life.

[0006] Poor environmental friendliness: The carbon emission of cement production reaches 0.8 - 1.0 tCO2 / t, and it is difficult to dispose of industrial solid waste, which does not conform to the development trend of green building materials.

[0007] Alkali-activated materials (AAM) use industrial waste residues (slag, fly ash, etc.) as precursors and generate gel phases through alkali activation reactions, and are regarded as potential substitutes for cement. However, due to the particularity of soft soil and soft rock slopes, when they are applied to the reinforcement of soft soil and soft rock slopes, there are still problems of insufficient durability, insufficient stability, and insufficient interfacial bonding strength. Summary of the Invention

[0008] To solve the above technical problems, the present invention aims to provide a grouting material for soft soil and soft rock slope reinforcement with high strength, high durability, and strong interfacial bonding strength, as well as a preparation method therefor.

[0009] One of the objectives of the present invention is to provide a grouting material for soft soil and soft rock slope reinforcement, and the grouting material comprises the following raw materials in parts by weight: 30 - 50 parts of granulated blast furnace slag 10 - 20 parts of steel slag 20 - 30 parts of fly ash 5 - 10 parts of silica fume 5 - 15 parts of metakaolin 20 - 30 parts of composite alkali activator 1 - 3 parts of nano-silica 0.5 - 1.6 parts of reinforcing fiber, and, 0.2 - 0.5 parts of silicone water repellent.

[0010] The granulated blast furnace slag has a particle size of 5 - 20 μm, the steel slag has a particle size of 3 - 15 μm, the fly ash has a particle size of 1 - 45 μm, and the silica fume has a particle size of 0.1 - 0.5 μm; the metakaolin has a particle size of 1 - 5 μm.

[0011] The composite alkali activator comprises 15 - 25 parts of sodium silicate solution, 2 - 5 parts of sodium hydroxide, and 3 - 5 parts of slow-release alkali activator. The concentration of the sodium silicate solution is 30% - 40%, and the modulus of sodium silicate is 1.2 - 1.8.

[0012] Preferably, the slow-release alkali activator comprises sodium carbonate and triethanolamine in a mass ratio of 1 - 2:1.

[0013] Preferably, the mass ratio of iron to calcium in the steel slag is 0.2 - 0.5:1, the D50 of the steel slag particle size is 8 μm, and the specific surface area ≥ 450 m 2 / kg.

[0014] Preferably, the D50 of the granulated blast furnace slag particle size is 10 μm, the specific surface area ≥ 450 m 2 / kg, and the molar ratio of CaO to SiO2 in the slag is 0.8 - 1.2:1, and the mass percentage content of Al2O3 is 8 - 15%.

[0015] Preferably, the D50 of the fly ash particle size is 20 μm.

[0016] Preferably, the D50 of the metakaolin particle size is 3 μm.

[0017] Preferably, the mass ratio of silica fume to nano-silica is 4 - 5:1.

[0018] Preferably, the length of the reinforcing fiber is 3-20 mm.

[0019] Preferably, the reinforcing fiber includes short fibers with a length of 3-6 mm, medium-length fibers with a length of 10-14 mm, and long fibers with a length of 16-20 mm.

[0020] Preferably, the amount of the short fibers is 0.25-0.85 parts, the amount of the medium-length fibers is 0.2-0.6 parts, and the amount of the long fibers is 0.05-0.15 parts.

[0021] Preferably, the reinforcing fiber includes one or more of basalt fiber, steel fiber, PVA fiber, and polypropylene fiber.

[0022] Preferably, the reinforcing fiber includes 0.2-0.6 parts of basalt fiber with a length of 12 mm, 0.05-0.15 parts of steel fiber with a length of 18 mm, 0.2-0.6 parts of PVA fiber with a length of 3 mm, and 0.05-0.25 parts of polypropylene fiber with a length of 6 mm.

[0023] The second object of the present invention is to provide a preparation method of a grouting material for soft soil and soft rock slope reinforcement, and the preparation method includes: First, add silica fume, nano-silica, and 5-10 parts of fly ash and mix them at a rotation speed of 200-300 rpm for 5-10 min, and then sequentially add granulated blast furnace slag, steel slag, the remaining fly ash, and organosilicon water repellent, and mix them at a rotation speed greater than or equal to 1000 rpm for 10-15 min; Then, add the organosilicon water repellent and stir at a rotation speed of 200-300 rpm for 3-5 min; Then, add a composite alkali activator and mix at a rotation speed of 300-500 rpm for 10-15 min; Then, add the reinforcing fiber and mix at a rotation speed of 200-300 rpm for 5-8 min.

[0024] Preferably, when the reinforcing fiber includes short fibers, medium-length fibers, and long fibers, first add the short fibers, stir at a rotation speed of 280-300 rpm for 3-5 min, then add the medium-length fibers and long fibers, adjust the rotation speed to 200-220 rpm, and stir for 3-5 min.

[0025] The beneficial effects of the present invention include: The grouting material described in the present invention uses industrial solid wastes such as granulated blast furnace slag, steel slag, and fly ash. Under the action of a composite alkali activator, it is combined with silica fume, metakaolin, nano-silica, and reinforcing fibers. On the one hand, a multi-particle size gradation is used to achieve full-range filling and form a dense packing structure. At the same time, silica fume and nano-silica cooperate with the microcrystal nuclei in the steel slag to refine the gel crystal grains, and the connectivity of the pores is reduced by filling the pores, which can significantly reduce the porosity. In cooperation with the silicone water repellent, the corrosion resistance of the material is improved. On the second hand, a composite gel network structure is formed. Under the action of the composite alkali activator, granulated blast furnace slag and metakaolin cooperate with each other to rapidly generate an intertwined composite gel network, constituting the early strength skeleton, ensuring the rapid formation of early strength. At the same time, calcium and iron in the steel slag can be adsorbed on the surface of the gel to form microcrystal nuclei, accelerating gel crosslinking and promoting the densification of the gel network. The steel slag can also continuously release Ca 2+ , which cooperates with the slow-release alkali activator to achieve continuous strength growth. On the third hand, a slurry-rock / soil interface transition layer is formed. The third metakaolin releases and reacts with active SiO2 in the rock / soil and nano-silica in the grouting material to generate a silicon-aluminum-rich transition layer at the slurry-rock / soil interface, improving the interface bonding strength. On the fourth hand, the addition of reinforcing fibers further improves the strength and toughness of the grouting material, enabling it to effectively bear the loads of soft soil and soft rock slopes and meeting the strength requirements for slope reinforcement. Detailed implementation manners

[0026] In the following description, certain specific details are included to provide a comprehensive understanding of the disclosed implementation manners. However, those skilled in the relevant art will recognize that the implementation manners can be achieved without one or more of these specific details, and other methods, components, materials, etc. can be used.

[0027] Unless otherwise required in the present invention, the words "comprising" and "including" should be interpreted in an open-ended, inclusive sense, that is, "including but not limited to".

[0028] The phrase "in one implementation manner" or "in the implementation manner" or "in a preferred implementation manner" or "in certain implementation manners" mentioned throughout this specification means that in at least one implementation manner, it includes the relevant specific reference elements, structures, or features described in that implementation manner. Therefore, the phrases "in one implementation manner" or "in the implementation manner" or "in a preferred implementation manner" or "in certain implementation manners" that appear at different positions throughout the specification do not necessarily all refer to the same implementation manner. In addition, the specific elements, structures, or features can be combined in one or more implementation manners in any appropriate way.

[0029] According to the first aspect of the present invention, a grouting material for soft soil and soft rock slope reinforcement is provided. The grouting material comprises the following raw materials in parts by weight: 30 - 50 parts of granulated blast furnace slag 10 - 20 parts of steel slag 20 - 30 parts of fly ash 5 - 10 parts of silica fume 5 - 15 parts of metakaolin 20 - 30 parts of composite alkali activator 1 - 3 parts of nano - silica 0.5 - 1.6 parts of reinforcing fiber, and, 0.2 - 0.5 parts of silicone water repellent

[0030] The particle size of the granulated blast furnace slag is 5 - 20 μm, the particle size of the steel slag is 3 - 15 μm, the particle size of the fly ash is 1 - 45 μm, the particle size of the silica fume is 0.1 - 0.5 μm; the particle size of the metakaolin is 1 - 5 μm.

[0031] The composite alkali activator includes 15 - 25 parts of water glass solution, 2 - 5 parts of sodium hydroxide, 3 - 5 parts of slow - release alkali activator, the concentration of the water glass solution is 30% - 40%, and the modulus of the water glass is 1.2 - 1.8.

[0032] In the present invention, through the particle size gradation of slag with a particle size of 5 - 20 μm, steel slag with a particle size of 3 - 15 μm, fly ash with a particle size of 1 - 45 μm, silica fume with a particle size of 0.1 - 0.5 μm and nano - silica, full - range filling in the range of 0.1 - 45 μm is achieved, forming a dense packing structure, which can significantly reduce the porosity.

[0033] Granulated blast furnace slag (CaO - SiO2 - Al2O3) dissociates rapidly under the excitation of OH - and releases Ca 2+ , [SiO4] 4- , [AlO4] 5- , and polymerizes to form C-(A)-S-H gel (CaO - SiO2 - H2O, Al 3+ partially replaces Si 4+ ), quickly forming an early - strength skeleton.

[0034] Metakaolin (Al2O3·2SiO2): After dehydroxylation, it forms active Al 3+ and Si 4+ , and reacts with [SiO4] 4- in the slag to form N - A - S - H gel (Na2O - Al2O3 - SiO2 - H2O).

[0035] The structures of C-(A)-S-H gel and N - A - S - H gel are intertwined to form a double - network structure.

[0036] In the present invention, the granulated blast furnace slag is, for example, 30 parts, 31 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 parts or 50 parts, and the metakaolin is, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts.

[0037] Calcium and iron in the steel slag form microcrystal nuclei by adsorbing on the surface of the gel, accelerating the cross-linking of C-(A)-S-H gel and promoting the densification of the gel network. At the same time, the slow dissolution of crystalline calcium silicate in the steel slag continuously releases Ca 2+ , which synergizes with the slow-release alkali activator in the composite activator to gradually release OH in the middle and late stages - synergistically, maintaining the alkalinity of the system, promoting the secondary reaction of low-activity components such as fly ash, and achieving continuous strength growth. The steel slag can complement the slag, providing an additional calcium source and microcrystal nucleus effect, promoting the densification of the gel network, and at the same time its slow-release characteristics extend the late strength growth. The difference in the calcium-silicon ratio between the granulated blast furnace slag and the steel slag can form a multi-scale gel structure, and the high-calcium gel fills the pores of the low-calcium gel, which can improve the density and impermeability. Fe2O3 in the steel slag enters the gel structure to form Fe-C-(A)-S-H, which can also improve the thermal stability.

[0038] In the present invention, the steel slag is, for example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts.

[0039] Nanosilica provides nucleation sites through its high specific surface area, reduces the crystallization activation energy of C-(A)-S-H gel, synergizes with the microcrystal nuclei in the steel slag to refine the gel grains, and reduces the pore connectivity by filling the pores; combined with the hydrophobic film formed by the organosilicon water repellent on the pore wall, it is beneficial to reduce the penetration rate of Cl - , SO4 2- and other plasma, and improves the corrosion resistance of the material. In the present invention, the nanosilica is, for example, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts or 3 parts.

[0040] The organosilicon water repellent is, for example, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts or 0.5 parts.

[0041] Specifically, the organosilicon water repellent includes silane water repellents, siloxane water repellents, silicone resin emulsion water repellents or silane-siloxane composite water repellents, and is preferably a combination of silicone resin emulsion water repellents and silane-siloxane composite water repellents.

[0042] Preferably, the mass ratio of the silicone emulsion type and the silane-siloxane composite water repellent is 1:1 to 3, for example, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8 or 1:3.

[0043] Meanwhile, the Al released by metakaolin 3+ reacts with the active SiO2 in the rock and soil to form a zeolite-like phase (such as sodalite, Na8Al6Si6O 24 Cl2). The Si-OH on the surface of nano-SiO2 reacts with the Al 3+ dissolved from metakaolin. The two cooperate with each other to form a silicon-aluminum-rich transition layer at the slurry-rock and soil interface, and the interfacial bonding strength is improved.

[0044] The addition of reinforcing fibers further improves the strength and toughness of the grouting material, can effectively withstand the loads of soft soil and soft rock slopes, and meets the strength requirements for slope reinforcement.

[0045] In the present invention, the reinforcing fibers are, for example, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts or 2 parts.

[0046] In the present invention, the silica fume is, for example, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts or 10 parts.

[0047] The fly ash is, for example, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts or 30 parts.

[0048] In a preferred embodiment of the present invention, the slow-release alkali activator includes sodium carbonate and triethanolamine with a mass ratio of 1-2:1. The mass ratio of sodium carbonate to triethanolamine is, for example, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2, and preferably 1.5:1.

[0049] In the present invention, sodium carbonate and triethanolamine with a mass ratio of 1-2:1 can cooperate to stabilize the modulus of water glass at 1.2-1.8. This is because sodium carbonate can gradually release OH in the middle and later stages - , and triethanolamine can be used as a complexing agent to delay OH -The release rate can continuously stimulate the low-activity components, which is beneficial to avoiding shrinkage cracks caused by excessive early reaction concentration, and can improve the toughness and volume stability of the material. The slow reaction characteristic of the slow-release alkali activator enables more active groups to form chemical bonds with the mineral components in soft soil and soft rock, and can significantly improve the interfacial shear strength. The synergistic effect of sodium carbonate and triethanolamine can inhibit the formation of easily eroded hydration products such as ettringite (AFt), and can improve the durability and erosion resistance of the material. At the same time, triethanolamine adsorbs on the surface of unreacted particles, and can also prevent agglomeration and improve dispersibility.

[0050] In a preferred embodiment of the present invention, the mass ratio of iron to calcium in the steel slag is 0.2 - 0.5:1, the particle size D50 of the steel slag is 8 μm, and the specific surface area is ≥ 450 m 2 / kg.

[0051] Preferably, the particle size D50 of the granulated blast furnace slag is 10 μm, the specific surface area is ≥ 450 m 2 / kg, the molar ratio of CaO to SiO2 in the slag is 0.8 - 1.2:1, and the mass percentage content of Al2O3 is 8 - 15%. The molar ratio of CaO to SiO2 in the slag is, for example, 0.8:1, 0.9:1, 1:1, 1.1:1 or 1.2:1, and the mass percentage content of Al2O3 is, for example, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%.

[0052] Preferably, the particle size D50 of the fly ash is 20 μm.

[0053] Preferably, the particle size D50 of the metakaolin is 3 μm.

[0054] In the present invention, by further optimizing the particle size structure and composition of each component, the matching of multi-scale particle size gradation and chemical activity is realized, further enhancing the densification of the structure of the grouting material, enhancing the synergistic effect of strength and toughness, with more stable volume and stronger crack resistance, and thus being more suitable for slope reinforcement of soft soil and soft rock.

[0055] In a preferred embodiment of the present invention, the mass ratio of silica fume to nano-silica is 4 - 5:1, such as 4:1, 4.1:1, 4.2:1, 4.3:1, 4.4:1, 4.5:1, 4.6:1, 4.7:1, 4.8:1, 4.9:1 or 5:1.

[0056] In the present invention, when the mass ratio of silica fume to the nano-silica is 4 - 5:1, the nano-silica and the silica fume are compounded at 1:4 - 5. On the one hand, the micron-sized particles of silica fume can be used to isolate nano-agglomeration; on the other hand, it is more conducive to the pore grading optimization of the grouting material, improving the density, facilitating early rapid nucleation and late silicon supplementation to further refine the gel structure. At the same time, the bonding strength at the interface between the slurry and the rock and soil, as well as the erosion resistance, are enhanced.

[0057] In a preferred embodiment of the present invention, the length of the reinforcing fiber is 3 - 20 mm, and the length of the reinforcing fiber is, for example, 3 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm or 20 mm.

[0058] Preferably, the reinforcing fiber includes short fibers with a length of 3 - 6 mm, medium-length fibers with a length of 10 - 14 mm, and long fibers with a length of 16 - 20 mm. The short fibers are, for example, 3 mm, 4 mm, 5 mm or 6 mm, the medium-length fibers are, for example, 10 mm, 11 mm, 12 mm, 13 mm or 14 mm, and the long fibers are, for example, 16 mm, 17 mm, 18 mm, 19 mm or 20 mm.

[0059] In the present invention, through the gradient distribution of short fibers (3 - 6 mm), medium-length fibers (10 - 14 mm) and long fibers (16 - 20 mm), a three-level toughening mechanism of "microscopic - mesoscopic - macroscopic" is realized: the short fibers form a dense network inside the grouting material, which is conducive to inhibiting the initiation of microcracks; the medium-length fibers can span millimeter-sized defects, which is conducive to improving the shear strength of the grouting material; the long fibers can penetrate the structurally weak areas and provide tensile support macroscopically. The synergistic effect of the multi-scale fiber system can further improve the fracture toughness of the material, reduce the risk of shrinkage cracking, and at the same time improve the interfacial bonding strength between the fiber and the matrix, significantly enhancing the integrity and long-term stability of the soft soil and soft rock slope reinforcement structure.

[0060] In a preferred embodiment of the present invention, the short fiber is 0.25 - 0.85 parts, the medium-length fiber is 0.2 - 0.6 parts, and the long fiber is 0.05 - 0.15 parts.

[0061] In the present invention, the short fiber is, for example, 0.25 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts or 0.85 parts. The medium-length fiber is, for example, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts or 0.6 parts. The long fiber is, for example, 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, 0.1 parts, 0.11 parts, 0.12 parts, 0.13 parts, 0.14 parts or 0.15 parts.

[0062] In a preferred embodiment of the present invention, the reinforcing fibers include one or several of basalt fibers, steel fibers, PVA fibers, and polypropylene fibers, preferably a combination of basalt fibers, steel fibers, PVA fibers, and polypropylene fibers. By using basalt fibers, steel fibers, PVA fibers, and polypropylene fibers in combination, a multi-scale synergistic reinforcement system is constructed, significantly improving the comprehensive performance of the grouting material.

[0063] Preferably, the reinforcing fibers include 0.2 - 0.6 parts of basalt fibers with a length of 12 mm, 0.05 - 0.15 parts of steel fibers with a length of 18 mm, 0.2 - 0.6 parts of PVA fibers with a length of 3 mm, and 0.05 - 0.25 parts of polypropylene fibers with a length of 6 mm.

[0064] According to the second aspect of the present invention, a preparation method of a grouting material for soft soil and soft rock slope reinforcement is provided. The preparation method includes: First, add silica fume, nano-silica, and fly ash and mix at a speed of 200 - 300 rpm for 5 - 10 min, then sequentially add granulated blast furnace slag, steel slag, the remaining fly ash, and organosilicon water repellent, and mix at a speed greater than or equal to 1000 rpm for 10 - 15 min; Then, add the organosilicon water repellent and stir at a speed of 200 - 300 rpm for 3 - 5 min; Then, add the composite alkali activator and mix at a speed of 300 - 500 rpm for 10 - 15 min; Then, add the reinforcing fibers and mix at a speed of 200 - 300 rpm for 5 - 8 min.

[0065] In a preferred embodiment of the present invention, when the reinforcing fibers include short fibers, medium-length fibers, and long fibers, first add the short fibers and stir at a speed of 280 - 300 rpm for 3 - 5 min, then add the medium-length fibers and long fibers, adjust the speed to 200 - 220 rpm, and stir for 3 - 5 min.

[0066] Examples The following examples are used to further illustrate the present invention in detail. It can be understood that the specific examples described herein are only used to explain the related invention, rather than limiting the invention. It should be noted that, without conflict, the examples in the present invention and the features in the examples can be combined with each other.

[0067] In the following examples, unless otherwise specified, each raw material component is a commercially available product.

[0068] Example 1 This example provides a grouting material for soft soil and soft rock slope reinforcement. The grouting material includes the following raw materials in parts by weight: Granulated blast furnace slag: 40 parts (D50 = 10 μm, molar ratio of CaO to SiO2 is 1:1, mass percentage of Al2O3 is 12%, specific surface area 480 m² / kg); Steel slag: 15 parts (D50 = 8 μm, mass ratio of iron to calcium is 0.3:1, specific surface area 480 m² / kg); Fly ash: 25 parts (D50 = 20 μm, Grade I); Silica fume: 8 parts (particle size 0.1 - 0.5 μm); Metakaolin: 10 parts (D50 = 3 μm); Compound alkali activator: 27 parts (20 parts of water glass, modulus 1.5, concentration 35%; 3 parts of NaOH; a total of 4 parts of sodium carbonate and triethanolamine, mass ratio 1.5:1); Nano - silica: 2 parts (mass ratio of silica fume to nano - silica is 4:1); Reinforcing fiber: 1.2 parts (0.4 parts of 12 - mm basalt fiber / 12 mm, 0.1 part of 18 - mm steel fiber, 0.4 part of 3 - mm PVA fiber, 0.3 part of 6 - mm polypropylene fiber); Organosilicon water repellent: 0.3 parts (0.1 part of silicone resin emulsion, using Evonik TEGO Phobe 1505; 0.2 part of silane - siloxane composite water repellent, using Kemira SILAX G - 800); Preparation method: First, add silica fume, nano - silica and fly ash and mix at 250 rpm for 5 - 10 min, then successively add granulated blast furnace slag, steel slag, the remaining fly ash and organosilicon water repellent, and mix at 1200 rpm for 10 - 15 min; Then, add the organosilicon water repellent and stir at 250 rpm for 3 - 5 min; Then, add the compound alkali activator and mix at 400 rpm for 10 - 15 min; Then, add PVA fiber and polypropylene fiber and mix at 250 rpm for 3 - 5 min, then add basalt fiber and steel fiber and adjust the rotation speed to 200 rpm, and stir for 3 - 5 min.

[0069] Example 2 Granulated blast furnace slag 30 parts, steel slag 20 parts, others are the same as Example 1.

[0070] Example 3 Granulated blast furnace slag 50 parts, steel slag 10 parts, others are the same as Example 1.

[0071] Example 4 The mass ratio of sodium carbonate to triethanolamine is 1:1, and the others are the same as in Example 1.

[0072] Example 5 The mass ratio of sodium carbonate to triethanolamine is 2:1, and the others are the same as in Example 1.

[0073] Example 6 10 parts of silica fume, 1 part of nano-silica, and the others are the same as in Example 1.

[0074] Example 7 5 parts of silica fume, 3 parts of nano-silica, and the others are the same as in Example 1.

[0075] Example 8 The mass ratio of iron to calcium in steel slag is 0.1:1, and the others are the same as in Example 1.

[0076] Example 9 The mass ratio of iron to calcium in steel slag is 0.6:1, and the others are the same as in Example 1.

[0077] Example 10 1.2 parts of 6mm polypropylene fiber is used as the reinforcing fiber, and the others are the same as in Example 1.

[0078] Example 11 1.2 parts of 12mm basalt fiber is used as the reinforcing fiber, and the others are the same as in Example 1.

[0079] Example 12 0.6 part of 6mm polypropylene fiber and 0.6 part of 12mm basalt fiber are used as the reinforcing fibers, and the others are the same as in Example 1.

[0080] Comparative Example 1 27 parts of composite alkali activator, including 22 parts of water glass with a modulus of 1.5 and a concentration of 35%, and 2 parts of NaOH. The slow-release alkali activator is not used.

[0081] The others are the same as in Example 1.

[0082] Comparative Example 2 55 parts of granulated blast furnace slag and 5 parts of steel slag, and the others are the same as in Example 1.

[0083] Comparative Example 3 The organosilicon water repellent is not used, and the others are the same as in Example 1.

[0084] Comparative Example 4 2 parts of 6mm polypropylene fiber is used as the reinforcing fiber, and the others are the same as in Example 1.

[0085] Comparative Example 5 Nano-silica is not used, and the others are the same as in Example 1.

[0086] The test results of Examples 1-12 and Comparative Examples 1-5 are shown in Table 1.

[0087] Table 1 Test Results of Examples 1-12 and Comparative Examples 1-5

Claims

1. A grouting material for soft soil and soft rock slope reinforcement, characterized in that, The grouting material comprises the following raw materials in parts by weight: 30-50 parts of granulated blast furnace slag 10-20 parts of steel slag 20-30 parts of fly ash 5-10 parts of silica fume 5-15 parts of metakaolin 20-30 parts of composite alkali activator 1-3 parts of nano-silica 0.5-1.6 parts of reinforcing fiber, and, 0.2-0.5 parts of silicone water repellent; The granulated blast furnace slag has a particle size of 5-20 μm, the steel slag has a particle size of 3-15 μm, the fly ash has a particle size of 1-45 μm, and the silica fume has a particle size of 0.1-0.5 μm; the metakaolin has a particle size of 1-5 μm; The composite alkali activator comprises 15-25 parts of sodium silicate solution, 2-5 parts of sodium hydroxide, and 3-5 parts of slow-release alkali activator. The concentration of the sodium silicate solution is 30%-40%, and the modulus of the sodium silicate is 1.2-1.

8.

2. The grouting material according to claim 1, wherein: The slow-release alkali activator comprises sodium carbonate and triethanolamine with a mass ratio of 1-2:

1.

3. The grouting material according to claim 1, wherein: The mass ratio of iron to calcium in the steel slag is 0.2 - 0.5:1, the particle size D50 of the steel slag is 8 μm, and the specific surface area is ≥ 450 m 2 / kg; The particle size D50 of the granulated blast furnace slag is 10 μm, and the specific surface area is ≥ 450 m 2 / kg. The molar ratio of CaO to SiO2 in the slag is 0.8 - 1.2:1, and the mass percentage content of Al2O3 is 8 - 15%; The D50 of the fly ash is 20 μm; The D50 of the metakaolin is 3 μm.

4. The grouting material according to claim 1, wherein: The mass ratio of the silica fume to the nano-silica is 4-5:

1.

5. The grouting material according to claim 1, wherein: The reinforcing fiber has a length of 3-20 mm, and the reinforcing fiber comprises short fibers with a length of 3-6 mm, medium-length fibers with a length of 10-14 mm, and long fibers with a length of 16-20 mm.

6. The grouting material according to claim 5, wherein: The short fibers are 0.25-0.85 parts, the medium-length fibers are 0.2-0.6 parts, and the long fibers are 0.05-0.15 parts.

7. The grouting material according to claim 1, wherein: The reinforcing fiber comprises one or more of basalt fiber, steel fiber, PVA fiber, and polypropylene fiber.

8. The grouting material according to any one of claims 1-7, wherein: The reinforcing fiber comprises 0.2-0.6 parts of basalt fiber with a length of 12 mm, 0.05-0.15 parts of steel fiber with a length of 18 mm, 0.2-0.6 parts of PVA fiber with a length of 3 mm, and 0.05-0.25 parts of polypropylene fiber with a length of 6 mm.

9. The preparation method of the grouting material according to any one of claims 1-8, characterized in that, The preparation method comprises: First, add silica fume, nano-silica, and 5-10 parts of fly ash and mix them at a rotation speed of 200-300 rpm for 5-10 min, then sequentially add granulated blast furnace slag, steel slag, the remaining fly ash, and silicone water repellent, and mix them at a rotation speed greater than or equal to 1000 rpm for 10-15 min; Then, add the silicone water repellent and stir at a rotation speed of 200-300 rpm for 3-5 min; Then, add the composite alkali activator and mix at a rotation speed of 300-500 rpm for 10-15 min; Then, add the reinforcing fiber and mix at a rotation speed of 200-300 rpm for 5-8 min.

10. The preparation method of the grouting material according to claim 9, wherein: When the reinforcing fibers include short fibers, medium-length fibers and long fibers, first add the short fibers and stir at a speed of 280-300 rpm for 3-5 minutes, then add the medium-length fibers and long fibers, adjust the speed to 200-220 rpm, and stir for 3-5 minutes.

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