High-fluidity solid waste-based solidified soil and preparation method thereof

Abstract

The invention provides high-fluidity solid waste-based solidified soil and a preparation method thereof, and belongs to the technical field of civil engineering. Based on a method for preparing the high-fluidity solid-waste-based solidified soil by using a grading mechanism as a main mechanism, an excitation mechanism as an auxiliary mechanism and a hydration mechanism as a background mechanism and adopting linkage synergy of the alkaline residues, the steel slag and the furnace slag and combining three forms of the alkaline residues, namely a solid state, a flow state and a mixed state, original-state utilization and high-doping utilization of the solid wastes are realized, and the doping amount of the dry solid wastes reaches 80-90%; a systematic construction method for applying the high-fluidity solid waste-based solidified soil to a foundation pit slope building and bottom protecting project is established, and standardized and large-scale construction of the foundation pit slope building and bottom protecting project of the foundation pit project is achieved. The high-fluidity solid waste-based solidified soil has high fluidity and high strength, can effectively fill various spaces, is suitable for various construction environments, and is high in construction speed and high in construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization technology, specifically to a method for preparing high-fluidity solid waste-based solidified soil. Background Technology

[0002] Slope construction and bottom protection in foundation pit engineering enhance the stability of the slope and bottom surface, playing a crucial role in the safety of foundation pit construction. Traditional methods for slope construction and bottom protection typically utilize materials such as concrete, rubble, bagged soil, or compacted fill. However, concrete slope construction is heavy and costly, heavily reliant on aggregate and requires sophisticated formwork support; rubble and bagged soil have low construction efficiency, high labor demands, and poor adaptability to various construction environments; compacted fill requires sophisticated machinery and is unsuitable for narrow, irregularly shaped spaces or situations where compaction machinery cannot easily access the site. Fluidized solidified soil, as a novel material, is gaining attention, but existing fluidized solidified soils struggle to meet the strength requirements under high fluidity conditions. This is because the alkali-activated effect is difficult to achieve under high fluidity and high water-to-solid ratio; the higher the water-to-solid ratio, the lower the compressive strength. Furthermore, there are no reports on systematic construction methods and applications of fluidized solidified soil in foundation pit engineering. Therefore, there is an urgent need for a low-cost, high-efficiency, environmentally adaptable, and high-strength solidified soil for slope construction and bottom protection in foundation pit engineering. Summary of the Invention

[0003] The purpose of this invention is to provide a high-fluidity solid waste-based solidified soil and its application method in foundation pit engineering. It can improve the resource utilization rate of alkali slag, steel slag, and furnace slag, achieve the purpose of high-mixing and original utilization of solid waste, and has both high fluidity and high strength. When used for slope protection in foundation pit engineering, it has low cost, high construction efficiency, strong environmental adaptability, and can realize standardized and large-scale construction.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a high-flowability solid waste-based solidified soil, characterized in that it comprises dry materials, additives, and water; The dry materials, by mass percentage, comprise 30-40% alkali slag, 15-25% steel slag, 20-25% furnace slag, and 10-20% cement, with the mass percentage of the above dry materials being 100%. Its preparation method is as follows: High-fluidity solid waste-based solidified soil is prepared by combining the three states of alkali slag—solid, fluid, and mixed—using the coordinated action of alkali slag, steel slag, and furnace slag. When the alkali slag is solid, it is mixed evenly with other solid materials, then water is added and stirred evenly, then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is fluid, the fluid alkali slag and water are mixed evenly to obtain an alkali slag slurry, then steel slag, furnace slag and cement are evenly mixed and added to the alkali slag slurry, then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is mixed, the fluid alkali slag and water are mixed and stirred evenly to obtain an alkali slag slurry; solid alkali slag, steel slag, furnace slag and cement are mixed evenly and added to the alkali slag slurry; then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is a mixture of solid alkali slag and fluid alkali slag, the mass ratio of the fluid alkali slag to the solid alkali slag is (70~90):(10~30).

[0005] The alkali residue is the waste residue generated during the ammonia-soda process for producing sodium carbonate, including calcium carbonate with a content of 30-50% and calcium sulfate with a content of 5-10%. Since the alkali residue contains the above-mentioned components, it can be used as the aforementioned dry alkali residue.

[0006] The steel slag is a byproduct produced during the converter steelmaking process. It includes oxide solid solutions containing calcium, magnesium, iron, and manganese, with an oxide solid solution content of 60-80%. Steel slag containing the above-mentioned components can be used as the aforementioned dry steel slag.

[0007] The slag is the waste residue discharged from the bottom of the furnace during coal combustion, including quartz with a content of 10-20% and mullite with a content of 10-15%; if the slag contains the above-mentioned components, it can be used as the above-mentioned dry slag.

[0008] Optionally, the admixture includes one or more of water-reducing agents, retarders, accelerators, early-strength agents, and antifreeze agents.

[0009] Optionally, the mass ratio of the admixture to cement is (0.1~0.5):100. Preferably, the mass ratio of the admixture to cement is 0.4:100.

[0010] Optionally, the mass ratio of water to dry material is (1~1.8):1.

[0011] Optionally, the particle size of the dry material is ≤2mm.

[0012] Optionally, the high-flowability solid waste-based solidified soil has a flowability of 250~350mm and a 28-day strength of 0.62~1.15MPa, achieving a balance between high flowability and high strength in the solid waste-based fluidized solidified soil.

[0013] The beneficial effects of this invention are as follows: 1. This invention proposes a high-fluidity solid waste-based solidified soil. Based on the synergistic effect of three mechanisms (gradation mechanism, activation mechanism, and hydration mechanism), it adopts the linkage of three slags (alkali slag, steel slag, and furnace slag) and combines the three states of alkali slag (solid, fluid, and mixed state) to prepare high-fluidity solid waste-based solidified soil. The dry weight of solid waste can reach 80-90%, achieving high solid waste content and effectively improving the utilization rate of bulk solid waste.

[0014] 2. This invention proposes the original utilization of alkali slag, steel slag, and furnace slag, which can be simply screened, avoiding the high energy consumption of drying and grinding; the preparation process is simple and convenient, and the construction process is highly efficient, which helps to realize the large-scale promotion of the high-flowability solid waste-based solidified soil.

[0015] 3. Under conditions of high fluidity (≥200mm) and high water-to-solid ratio (ratio of water to dry mass) (≥1.0), abundant free water weakens the alkali activation effect. The higher the water-to-solid ratio, the weaker the alkali activation effect and the lower the compressive strength. This invention utilizes the synergistic effect of three mechanisms under high fluidity, with the three slags matching as the main mechanism, alkali slag activation as the auxiliary mechanism, and cement hydration as the background mechanism, to achieve a balance between high fluidity (250~350mm) and high strength (0.62~1.15MPa) of solid waste-based fluidized solidified soil.

[0016] 4. This invention uses the high-fluidity solid waste-based solidified soil as a slope protection material for foundation pit engineering, establishes a systematic construction method for the high-fluidity solid waste-based solidified soil, and realizes the standardized and large-scale construction of the high-fluidity solid waste-based solidified soil in foundation pit engineering. It has significant practical implications for improving construction efficiency, reducing construction costs, and realizing the large-scale resource utilization of alkali slag, steel slag, and furnace slag. Attached Figure Description

[0017] Figure 1 XRD diffraction patterns of Examples 1-3 of the high-flowability solid waste-based solidified soil provided by the present invention; Figure 2 Particle size distribution diagrams of high-fluidity solid waste-based solidified soil, alkaline slag, steel slag, and furnace slag provided by this invention; Figure 3 A construction flowchart for the application of high-fluidity solid waste-based solidified soil in slope construction and bottom protection of foundation pit engineering provided by the present invention. Figure 4 An elevation view of the application of the high-flowability solid waste-based solidified soil provided by the present invention in slope construction and bottom protection of foundation pit engineering. Figure 5 A plan view of the application of the high-flowability solid waste-based solidified soil provided by the present invention in slope construction and bottom protection of foundation pit engineering. Figure 6 The present invention provides on-site construction drawings for slope construction and bottom protection of foundation pit engineering using high-flowability solid waste-based solidified soil. Detailed Implementation

[0018] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] This invention provides a high-flowability solid waste-based solidified soil, comprising dry materials, additives, and water; The dry materials, by mass percentage, comprise 30-40% alkali slag, 15-25% steel slag, 20-25% furnace slag, and 10-20% cement, with the mass percentage of the above dry materials being 100%. Its preparation method is as follows: High-fluidity solid waste-based solidified soil is prepared by combining the three states of alkali slag—solid, fluid, and mixed—using the coordinated action of alkali slag, steel slag, and furnace slag. When the alkali slag is solid, it is mixed evenly with other solid materials, then water is added and stirred evenly, then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is fluid, the fluid alkali slag and water are mixed evenly to obtain an alkali slag slurry, then steel slag, furnace slag and cement are evenly mixed and added to the alkali slag slurry, then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is mixed, the fluid alkali slag and water are mixed and stirred evenly to obtain an alkali slag slurry; solid alkali slag, steel slag, furnace slag and cement are mixed evenly and added to the alkali slag slurry; then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is a mixture of solid alkali slag and fluid alkali slag, the mass ratio of the fluid alkali slag to the solid alkali slag is (70~90):(10~30).

[0020] The alkaline residue is the waste residue generated during the ammonia-soda process for producing sodium carbonate, including calcium carbonate with a content of 30-50% and calcium sulfate with a content of 5-10%. The steel slag is a byproduct of the converter steelmaking process, comprising oxide solid solutions containing calcium, magnesium, iron, and manganese, with an oxide solid solution content of 60-80%. The slag is the waste residue discharged from the bottom of the furnace during coal combustion, comprising 10-20% quartz and 10-15% mullite. The cement is ordinary Portland cement with a strength grade of 42.5.

[0021] The admixture includes one or more of water-reducing agents, retarders, accelerators, early-strength agents, and antifreeze agents. More preferably, it includes one or more of water-reducing agents, retarders, and accelerators; the water-reducing agent adjusts the fluidity, and the retarder and accelerator adjust the setting time to achieve the workability, pumpability, and construction interval required for construction.

[0022] The water is tap water and / or treated wastewater that meets the requirements of the standard for concrete water use JGJ63.

[0023] The mass ratio of the admixture to cement is (0.1~0.5):100. Preferably, the mass ratio of the admixture to cement is 0.4:100.

[0024] The mass ratio of water to dry material is (1~1.8):1. Preferably, the mass ratio of water to dry material is 1.5:1.

[0025] Alkali residue is the waste residue generated during the ammonia-soda process for producing sodium carbonate. Its main components are calcium carbonate and calcium sulfate, with contents of 40.2% and 8.1%, respectively.

[0026] Steel slag is a byproduct of the converter steelmaking process. Its main components are solid solutions of oxides of calcium, magnesium, iron and manganese, with a content of 70.7%.

[0027] The slag is the portion discharged from the bottom of the furnace during coal combustion. Its main components are quartz and mullite, with contents of 15.4% and 12.6%, respectively.

[0028] This invention also provides a method for applying the high-flowability solid waste-based solidified soil described above in foundation pit engineering. The high-flowability solid waste-based solidified soil is poured into the foundation pit bottom protection and / or slope construction areas.

[0029] When the dimensions of the foundation pit bottom protection and / or slope protection are larger than the dimensions of a single pouring area and / or the pouring thickness is greater than the thickness of a single layer, the pouring shall be carried out in sections and / or layers. The thickness of a single layer of the foundation pit bottom protection is 0.15m, and the thickness of a single layer of the foundation pit slope protection is 0.5m.

[0030] In this invention, the time interval from the completion of preparation to the completion of pouring of the high-fluidity solid waste-based solidified soil is preferably 3-4 hours. When the time interval is within the above range, the admixture of the high-fluidity solid waste-based solidified soil is preferably a water-reducing agent; when the time interval is less than the above range, the admixture is preferably a combination of a water-reducing agent and a retarder; when the time interval is greater than the above range, the admixture is preferably a combination of a water-reducing agent and a setting accelerator. This invention controls the time interval within the above range, which satisfies the time required to complete the construction steps while avoiding a decrease in the fluidity of the high-fluidity solid waste-based solidified soil due to prolonged time and accelerated hydration reaction, thus facilitating construction.

[0031] In this invention, water must not be added to the high-fluidity solid waste-based solidified soil during the pouring process.

[0032] In this invention, the preferred method for applying the high-flowability solid waste-based solidified soil in the bottom protection of foundation pit engineering includes: pouring high-flowability solid waste-based solidified soil at the bottom protection location of the foundation pit.

[0033] The present invention preferably involves excavating the surface soil at the bottom of the foundation pit before pouring the foundation pit protection layer, then pumping out the water accumulated at the bottom of the foundation pit, and then leveling the surface.

[0034] In this invention, when the size of the foundation pit bottom protection area is greater than the size of a single pouring area and / or the pouring thickness is greater than the thickness of a single layer, the pouring is preferably carried out in sections and / or layers.

[0035] In this invention, the thickness of the single-layer casting is preferably 0.1~0.5m. Preferably, an elevation steel wire rope is installed for each layer thickness, and the steel wire rope is taut and sturdy.

[0036] In this invention, it is preferable to pour the concrete to the required elevation in one go during the layered pouring process, and it is prohibited to use the method of "applying thin layers" to achieve the required elevation.

[0037] After each layer of high-flowability solid waste-based solidified soil is poured, this invention preferably covers it with a plastic film and / or geotextile for moisture retention and curing after the free water on the surface of each layer of high-flowability solid waste-based solidified soil has receded. In this invention, the curing time for the top layer is preferably ≥7 days; the curing time for the other layers is preferably until final setting. This invention preferably uses manual film covering or an automated film covering machine for film covering.

[0038] When the pouring area is in a narrow or concealed location where it is difficult to cover with plastic film or geotextile, the present invention preferably employs other curing measures based on the site environment. The present invention does not impose any specific limitations on the operation of these other curing measures; curing measures well-known to those skilled in the art can be used.

[0039] In this invention, the single casting area is preferably rectangular; the side length of the single casting area is preferably 20~40m.

[0040] In this invention, expansion joints are preferably provided between the pouring areas; the width of the expansion joint is preferably 1-3 mm, more preferably 2 mm; the pouring construction joint is preferably combined with the expansion joint. The expansion joints in this invention prevent cracks from forming in the solidified soil of high-flowability solid waste base due to shrinkage.

[0041] In this invention, the preferred method for applying the high-flowability solid waste-based solidified soil in the slope construction of foundation pit engineering includes: pouring high-flowability solid waste-based solidified soil at the slope construction site of the foundation pit.

[0042] The present invention preferably uses the existing walls and / or soil and slope bottom of the foundation pit as the foundation to support the formwork, and then pours high-flowability solid waste base solidified soil.

[0043] In this invention, the surface soil of the slope bottom is preferably excavated and then leveled before the template is set up.

[0044] In this invention, anchor rods are preferably installed on the surface of the existing wall or soil of the foundation pit. The anchor rods are used to fix the formwork. In one embodiment, the anchor rods are inserted obliquely into the existing wall or soil of the foundation pit by 0.3m.

[0045] The slope of the slope created in this invention is 1:2; during the slope creation, the pouring of the high-flowability solid waste-based solidified soil is preferably carried out in sections and / or layers.

[0046] In this invention, expansion joints are preferably installed every 10-15m along the extension direction of the original wall or soil of the foundation pit; the width of the expansion joint is preferably 1-3mm, more preferably 2mm. This invention uses expansion joints to prevent cracks from forming in the solidified soil of high-flowability solid waste foundations due to shrinkage.

[0047] In this invention, the thickness of the single-layer pouring is preferably 0.5~1.0m. In this invention, the operation of layered pouring of the high-flowability solid waste base solidified soil during slope construction is preferably the same as the operation of layered pouring of the high-flowability solid waste base solidified soil during bottom protection, and will not be repeated here.

[0048] This invention applies high-flowability solid waste-based solidified soil to slope protection in foundation pit engineering. Due to its good fluidity and self-compacting properties, it can effectively fill narrow and deep slope-building spaces, achieve uniform compaction of the high-flowability solid waste-based solidified soil, and improve the integrity of the filling area. It can cover a large area of ​​planar space in a short time to achieve foundation pit bottom protection. It can simplify the construction process and improve work efficiency and construction safety through an integrated construction method.

[0049] The preferred construction flow chart for the application of high-flowability solid waste-based solidified soil in slope construction and bottom protection of foundation pit engineering provided by this invention is as follows: Figure 3 As shown, the process includes site cleaning and leveling, formwork support, raw material transportation, material mixing, on-site pouring, membrane curing, and geotextile insulation.

[0050] The technical solution of this invention will be clearly and completely described below with reference to the embodiments thereof. The alkaline slag, as tested by a particle size analyzer, has a sand content of 15.2%, a powder content of 68.5%, and a clay content of 16.3%. The steel slag, as tested by a particle size analyzer, has a sand content of 36.1%, a powder content of 61.1%, and a clay content of 2.8%. The furnace slag, as tested by a particle size analyzer, has a sand content of 31.0%, a powder content of 61.6%, and a clay content of 7.4%. The water-reducing agent is a polycarboxylate water-reducing agent with a water reduction rate of 29%, which is a commercially available product. All other raw materials used are commercially available products.

[0051] Example 1: A high-flowability solid waste-based solidified soil, composed of dry materials, water-reducing agent and water; The dry material, by mass percentage, consists of 40% alkali slag, 25% steel slag, 25% furnace slag, and 10% cement; the mass ratio of water-reducing agent to cement is 0.4:100, and the water-to-solid ratio is 1.5:1. The preparation method of the high-flowability solid waste-based solidified soil is as follows (the alkali slag is solid): solid alkali slag, steel slag, furnace slag and cement are mixed evenly, then water is added and stirred evenly, then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain high-flowability solid waste-based solidified soil with a flowability of 330mm; the 7d, 14d and 28d strengths are 0.32MPa, 0.51MPa and 0.62MPa, respectively.

[0052] Example 2: A high-flowability solid waste-based solidified soil, composed of dry materials, water-reducing agent and water; The composition by mass percentage is: 35% alkali slag, 25% steel slag, 25% furnace slag, and 15% cement; the mass ratio of water-reducing agent to cement is 0.4:100, and the water-to-solid ratio is 1.5:1. The preparation method of the high-fluidity solid waste-based solidified soil is as follows (the alkali slag is in a fluid state): the fluid alkali slag and water are mixed evenly to obtain an alkali slag slurry. Then, steel slag, furnace slag and cement are mixed evenly and added to the alkali slag slurry. A water-reducing agent is then added and stirred evenly. The mixture is then filtered through a 2mm filter screen to obtain high-fluidity solid waste-based solidified soil with a fluidity of 310mm. The strengths at 7d, 14d and 28d are 0.43MPa, 0.72MPa and 0.90MPa, respectively.

[0053] Example 3: A high-flowability solid waste-based solidified soil, composed of dry materials, water-reducing agent and water; By mass percentage, the composition is: 30% alkali slag, 25% steel slag, 25% furnace slag, and 20% cement; the mass ratio of water-reducing agent to cement is 0.4:100, and the water-to-solid ratio is 1.5:1. The preparation method of the high-flowability solid waste-based solidified soil is as follows (the alkali slag is in a mixed state): the fluid alkali slag and water are mixed and stirred evenly to obtain an alkali slag slurry; the solid alkali slag, steel slag, furnace slag and cement are mixed evenly and added to the alkali slag slurry; the mass ratio of alkali slag slurry to solid alkali slag is 76:24; then a water-reducing agent is added and stirred evenly, and the mixture is filtered through a 2mm filter screen to obtain high-flowability solid waste-based solidified soil with a flowability of 290mm; the 7d, 14d and 28d strengths are 0.60MPa, 0.93MPa and 1.15MPa, respectively.

[0054] The 28-day mineral evolution process of Examples 1-3 is as follows: Figure 1As shown in the left figure, the main mineral components (2q: 5-70) are ettringite (AFt), calcite, quartz and mullite; Figure 1 The figure on the right shows the quantitative analysis of the mineral phases in Examples 1-3. As the cement content in Examples 1-3 increased (10%, 15%, 20%), the AFt content gradually increased significantly (39.4%, 43.5%, 46.5%), indicating that the cement hydration was sufficient. However, the calcium carbonate content did not change much (33.5%, 34.7%, 36.8%), indicating that although the alkali slag participated in the reaction, the reaction was weak. This is because under the conditions of high fluidity and high water-to-solid ratio, the free water diluted the alkalinity of the alkali slag and weakened its activating properties.

[0055] The higher the fluidity and the greater the water-to-solid ratio, the more difficult it is for the alkali slag to exert its activating effect due to the dilution effect of free water. When the fluidity is ≥200mm and the water-to-solid ratio is ≥1.0, the activating effect of the alkali slag is relatively weak and has a slight auxiliary effect. The main role is the blending and appropriate gradation of alkali slag, steel slag and furnace slag under the background of cement hydration.

[0056] Comparative Example 1 The difference from Example 1 is as follows: The steel slag content is 50%, and the furnace slag content is 0%. The fluidity is 340 mm; the strengths at 7d, 14d, and 28d are 0.28 MPa, 0.44 MPa, and 0.59 MPa, respectively.

[0057] Comparative Example 2 The difference from Example 1 is as follows: The steel slag content is 0%, and the furnace slag content is 50%. The fluidity is 345 mm; the strengths at 7d, 14d, and 28d are 0.23 MPa, 0.39 MPa, and 0.53 MPa, respectively.

[0058] Comparative Example 3 The difference from Example 2 is as follows: The steel slag content is 50%, and the furnace slag content is 0%. The fluidity is 320 mm; the strengths at 7d, 14d, and 28d are 0.36 MPa, 0.59 MPa, and 0.74 MPa, respectively.

[0059] Comparative Example 4 The difference from Example 2 is as follows: The steel slag content is 0%, and the furnace slag content is 50%. The fluidity is 325 mm; the strengths at 7d, 14d, and 28d are 0.33 MPa, 0.48 MPa, and 0.69 MPa, respectively.

[0060] Comparative Example 5 The difference from Example 3 is as follows: The steel slag content is 50%, and the furnace slag content is 0%. The fluidity is 300 mm; the strengths at 7d, 14d, and 28d are 0.49 MPa, 0.78 MPa, and 0.96 MPa, respectively.

[0061] Comparative Example 6 The difference from Example 3 is as follows: The steel slag content is 0%, and the furnace slag content is 50%. The fluidity is 305 mm; the strengths at 7d, 14d, and 28d are 0.45 MPa, 0.72 MPa, and 0.93 MPa, respectively.

[0062] The compressive strength and improvement benefits of the high-flowability solid waste-based solidified soil in Examples 1-3 and Comparative Examples 1-6 were tested according to the JGJ T 233 standard. The results are shown in Tables 1, 2, 3 and 4. As can be seen from Tables 2, 3, and 4, when the cement and alkali slag dosages are the same, the three slags—alkali slag, steel slag, and furnace slag—are well-matched and compatible, as shown in Examples 1, 2, and 3. Under conditions of similar fluidity, their 7-day, 14-day, and 28-day strengths are significantly higher than those of Comparative Examples 1-2, 3-4, and 5-6. The strength improvement benefits at different ages range from 117% to 150%, remaining relatively stable at around 130%, demonstrating a very significant improvement. Figure 2 As shown, steel slag particles are relatively coarse, alkali slag particles are relatively fine, and furnace slag is in a moderate and coordinated position. Under the background of cement hydration, the three slags can form a stable interlocking structure, realize the linkage and synergy of the three slags, and achieve a balance between high fluidity and high strength.

[0063] To further illustrate the application method of high-flowability solid waste-based solidified soil in slope construction and bottom protection of foundation pit engineering, the following detailed application examples are provided, which adopt the above-mentioned Examples 1 to 3.

[0064] Elevation diagrams of various applications of high-flowability solid waste-based solidified soil in slope construction and bottom protection of foundation pit engineering are shown below. Figure 4 As shown, Figure 4 1 is the top of the wall (40mm wide), 2 is the anchor rod (inserted 30cm into the wall, with a vertical distance of 25cm between anchor rods), 3 is the solidified soil of high-flowability solid waste base, 4 is the original vertical wall of the foundation pit project, 5 is the formwork, 6 is the plastic film, 7 is the layered pouring (single layer thickness of 30cm), the slope of the slope is 1:2, the vertical height of the slope is 100cm, the vertical distance between the bottom of the foundation pit and the bottom of the slope is 500cm, and the horizontal length of the bottom of the foundation pit is 50m.

[0065] Plan view diagrams of various applications of high-flowability solid waste-based solidified soil in foundation pit engineering bottom protection are shown below. Figure 5 As shown, Figure 5 1 is the slope protection, 2 is the foundation pit, and 3 is the expansion joint.

[0066] The construction environment in each application example is autumn and rainless.

[0067] Application Example 1 The high-fluidity solid waste-based solidified soil from Example 1 was prepared according to... Figure 4 Slope construction for foundation pit engineering: The specific steps are as follows: (1) Excavate the surface soil at the bottom of the slope, remove garbage and impurities, and then level it; (2) Install anchor rods at the existing vertical walls of the foundation pit and set up formwork; set expansion joints every 15m along the extension direction of the wall (the width of the expansion joint is 2mm). (3) Pour high-flowability solid waste base solidified soil into the template, and pour in different areas and layers. Each layer is 0.50m thick. Set elevation steel wire ropes according to the thickness of each layer. The steel wire ropes are taut and straight. Pour to the elevation in one go. After the free water on the surface of each layer of high-flowability solid waste base solidified soil recedes, cover it with plastic film and geotextile for moisturizing and curing. The curing time of the top layer is 7 days, and the other layers are cured until final set.

[0068] Application Example 2 The high-fluidity solid waste-based solidified soil in Example 2 was prepared according to... Figure 4 The specific steps for foundation pit bottom protection are as follows: (1) Excavate the surface soil at the bottom of the foundation pit, clean up the garbage and impurities, then pump out the water at the bottom of the foundation pit, and then level it. (2) High-flowability solid waste base solidified soil is poured at the bottom of the foundation pit. The pouring is carried out in different areas and layers. The area size is 20m×40m. Expansion joints (the width of the expansion joint is 2mm) are set between each area. The thickness of each layer is 0.15m. Elevation steel wire ropes are set according to the thickness of each layer. The steel wire ropes are taut and straight. The soil is poured to the elevation in one go. After the free water on the surface of each layer of high-flowability solid waste base solidified soil recedes, it is covered with plastic film and geotextile for moisture retention and curing. The curing time of the top layer is 7 days, and the other layers are cured until the final set.

[0069] Application Example 3 The high-fluidity solid waste-based solidified soil in Example 3 was prepared according to... Figure 4 The specific steps for slope construction and bottom protection in foundation pit engineering are as follows: (1) Excavate the surface soil at the bottom of the slope, remove garbage and impurities, and then level it; (2) Install anchor rods at the existing vertical walls of the foundation pit and set up formwork; set expansion joints at intervals of 15m along the extension direction of the wall (the width of the expansion joint is 2mm). (3) Pour high-flowability solid waste base solidified soil into the template, and pour in different areas and layers. Each layer is 0.50m thick. Set elevation steel wire ropes according to the thickness of each layer. The steel wire ropes are taut and straight. Pour to the elevation in one go. After the free water on the surface of each layer of high-flowability solid waste base solidified soil has receded, cover it with plastic film and geotextile for moisturizing and curing. The curing time for the top layer is 7 days, and the other layers are cured until the final set. (4) Excavate the surface soil at the bottom of the foundation pit, clean up the garbage and impurities, then pump out the water at the bottom of the foundation pit and then level it. (5) Pour high-flowability solid waste base solidified soil at the bottom of the foundation pit, and pour it in different areas and layers. The area size is 20m×40m. Expansion joints (expansion joint width is 2mm) are set between each area. The thickness of each layer is 0.15m. Set elevation steel wire ropes according to the thickness of each layer. The steel wire ropes are taut and straight. Pour to the elevation in one go. After the free water on the surface of each layer of high-flowability solid waste base solidified soil recedes, cover it with plastic film and geotextile for moisturizing and curing. The curing time of the top layer is 7 days, and the other layers are cured until final set.

[0070] The on-site construction drawings for slope construction and bottom protection of foundation pit engineering using high-flowability solid waste-based solidified soil in Application Example 3 are as follows: Figure 6 As shown.

[0071] Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The above descriptions are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-flowability solid waste-based solidified soil, characterized in that, Includes dry ingredients, additives, and water; The dry materials, by mass percentage, comprise 30-40% alkali slag, 15-25% steel slag, 20-25% furnace slag, and 10-20% cement, with the mass percentage of the above dry materials being 100%. Its preparation method is as follows: High-fluidity solid waste-based solidified soil is prepared by combining the three states of alkali slag—solid, fluid, and mixed—using the coordinated action of alkali slag, steel slag, and furnace slag. When the alkali slag is solid, it is mixed evenly with other solid materials, then water is added and stirred evenly, then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is fluid, the fluid alkali slag and water are mixed evenly to obtain an alkali slag slurry, then steel slag, furnace slag and cement are evenly mixed and added to the alkali slag slurry, then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is mixed, the fluid alkali slag and water are mixed and stirred evenly to obtain an alkali slag slurry; solid alkali slag, steel slag, furnace slag and cement are mixed evenly and added to the alkali slag slurry; then water-reducing agent is added and stirred evenly, and then filtered through a 2mm filter screen to obtain the high-fluidity solid waste-based solidified soil; when the alkali slag is a mixture of solid alkali slag and fluid alkali slag, the mass ratio of the fluid alkali slag to the solid alkali slag is (70~90):(10~30).

2. The high-fluidity solid waste-based solidified soil and its preparation method according to claim 1, characterized in that, The admixtures include one or more of the following: water-reducing agents, retarders, accelerators, early-strength agents, and antifreeze agents.

3. The high-flowability solid waste-based solidified soil and its preparation method according to claim 1, characterized in that, The mass ratio of the admixture to cement is (0.1~0.5):

100.

4. The high-fluidity solid waste-based solidified soil and its preparation method according to claim 1, characterized in that, The mass ratio of water to dry material is (1~1.8):

1.

5. The high-fluidity solid waste-based solidified soil and its preparation method according to claim 1, characterized in that, The particle size of the dry material is ≤2mm.

6. The high-flowability solid waste-based solidified soil and its preparation method according to claim 1, characterized in that, The fluidity of the high-fluidity solid waste-based solidified soil is 250~350mm.

7. The high-fluidity solid waste-based solidified soil and its preparation method according to claim 1, characterized in that, The 28-day strength of the high-fluidity solid waste-based solidified soil is 0.62~1.15 MPa.

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