A method, system, product, and preparation method for determining the formulation of a high-ductility composite material based on lake and reservoir sediment.

Abstract

This invention discloses a method, system, product, and preparation method for determining the formulation of a high-ductility composite material based on lake and reservoir sediment, belonging to the fields of water conservancy and hydropower, transportation, and building materials technology. The determining system includes: an acquisition module for acquiring the particle distribution characteristics of a modified mixture of lake and reservoir sediment-red mud-steel slag, blast furnace ore powder, nano-SiO2, cement, and ultrafine lake and reservoir sand; a first determining module for determining a formulation optimization model of the mixed powder based on the acquired particle distribution characteristics of the mixture; the formulation optimization model of the mixed powder includes a first objective function and a first constraint condition; and a second determining module for determining the formulation of the high-ductility composite material based on the formulation optimization model of the mixed powder and the basic model of the auxiliary agents. The above system is then used to determine the optimal formulation and prepare a high-ductility hydraulic composite material based on lake and reservoir sediment, which not only utilizes the lake and reservoir sediment but also produces a composite material with good deformation performance and strong crack resistance.

Description

Technical Field

[0001] This invention belongs to the fields of water conservancy and hydropower, transportation, and building materials technology, and particularly relates to a method, system, product, and preparation method for determining a high-ductility composite material formulation based on lake and reservoir silt. Background Technology

[0002] Due to soil erosion and human activities, reservoirs are severely silted up and lakes are shrinking, reducing their functionality, safety, and overall benefits. This has become one of the bottlenecks restricting my country's economic and social development.

[0003] my country currently has approximately 98,000 reservoirs with a total capacity of 930.6 billion cubic meters. Affected by soil erosion and human activities, these reservoirs generally experience varying degrees of siltation and capacity shrinkage, with an average annual siltation loss rate of about 2%. Small and medium-sized reservoirs, in particular, suffer from more severe siltation after years of operation due to a lack of sediment flushing facilities. Soil erosion and wastewater discharge also contribute to the fragmentation, blockage, and poor connectivity of river and lake systems, severely impacting their integrity and ecosystems. Current technologies for the treatment and resource utilization of reservoir silt include dewatering, building material processing, sludge landfilling, sludge composting, sludge co-firing, chemical consolidation, anaerobic digestion, and dry distillation. Among these, the dewatering and subsequent use of reservoir silt for building material processing is an effective way to achieve large-scale disposal. Lake and reservoir sediments are large in scale and have a wide range of particle sizes, including large stones and sands as well as extremely fine silt and clay particles. Usually, some sediments that meet the standards for construction sand and gravel after separation can be used directly. However, the content of extremely fine silt and extremely fine clay particles is large and their composition is complex. Their large-scale green and efficient disposal has become a key technical bottleneck restricting the safety of water projects and the restoration of river and lake ecosystems.

[0004] In recent years, with the implementation of pilot projects for ecological dredging of lakes and reservoirs, some studies have explored the resource utilization of extremely fine sediment, including its production into expanded clay, bricks, cement, and as construction soil. For example, Chinese invention patent CN115745483A describes a method using polycarbonate and asphalt particles with particle sizes of 200-500 μm to bind fine sediment particles under a high-speed airflow spray at temperatures below 120°C, producing modified spherical particles. Cement, silica fume, latex powder, steel fiber, water, and coarse sediment particles of 80-180 μm are then added to create a high-strength binder. This patented technology utilizes only a portion of the extremely fine and coarse particles in the sediment, resulting in a binder with a compressive strength of approximately 100 MPa, but it does not fully utilize the fully graded sediment. Chinese invention patent CN115677279A provides a method for developing and preparing a cementitious mixture for ultrafine granular silt deposits in reservoirs. Based on the analysis of silt moisture content, mud content, particle size distribution, and performance, it proposes optimal mix proportions for cementitious material systems combining cement + silica fume and cement + silica fume + fly ash + ultrafine powder. This invention first determines the cementitious conditions and maps the distribution of usable granular materials through drilling, layered sampling, and analysis. Then, silt deposits meeting these cementing conditions are collected and cemented. However, in reservoir dredging practices, the scale of silt deposits is enormous. From an environmental and functional restoration perspective, all silt must be disposed of on land, rather than selectively choosing suitable gradations. Therefore, the applicability of the aforementioned patented technology has certain limitations.

[0005] Based on existing research, the technology for large-scale and resource utilization of ultrafine particles of lake and reservoir sediment is still immature. Utilizing the characteristics of ultrafine sediment particles and co-processing them with watershed-specific solid waste, combined with the needs of water conservancy construction and watershed environmental protection, developing high-toughness composite materials with good deformation adaptability is an innovative approach to the resource utilization of ultrafine particles of lake and reservoir sediment. This approach can provide an innovative path for the last mile of ecological dredging of lakes and reservoirs, and can also contribute innovative solutions for the co-processing of diverse solid wastes in watersheds. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a method, system, product, and preparation method for determining the formulation of a high-ductility composite material based on lake and reservoir sediment. This invention utilizes silt and ultrafine sand, primarily composed of clay particles, separated from lake and reservoir sediment. Combined with watershed solid waste such as steel slag and red mud, the silt undergoes alkali-thermal modification and is used as a component of the cementitious material. The ultrafine sand is sieved to obtain extremely fine particles with particle sizes below 300 μm and 150 μm. Modified carbon fibers are then incorporated to formulate hydraulic pumping composite materials and spray repair composite materials, respectively, achieving the synergistic treatment and high-value utilization of multiple solid wastes. Furthermore, the hydraulic high-ductility composite material prepared from lake and reservoir sediment exhibits excellent deformation performance and strong crack resistance. It not only solves the problem of the difficulty in resource utilization of extremely fine particles from lake and reservoir sediment but also utilizes waste carbon fibers for reinforcement and toughening. The preparation process has advantages such as good processability, simple manufacturing process, and no environmental pollution. It can be used for special parts such as large deformation sections of water conservancy and hydropower projects or the repair of pipelines for the Yangtze River protection project.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] One of the technical solutions of this invention:

[0009] A system for determining the formulation of high-ductility composite materials based on lake and reservoir sediments, comprising:

[0010] The acquisition module acquires the particle distribution characteristics of modified mixtures of lake and reservoir silt-red mud-steel slag, blast furnace ore powder, nano-SiO2, cement, and lake and reservoir ultrafine sand.

[0011] The first determination module, with the maximum amount of ultrafine sand from lakes and reservoirs as the target, is used to determine the formula optimization model of the mixed powder (composed of five raw materials) based on the obtained particle distribution characteristics of the modified mixture of lake silt-red mud-steel slag, blast furnace ore powder, nano SiO2, cement and ultrafine sand from lakes and reservoirs.

[0012] The formulation optimization model for the mixed powder includes a first objective function and a first constraint condition;

[0013] The second determining module is used to determine the formulation of the high-ductility composite material based on the formulation optimization model of the mixed powder and the basic model of the auxiliary agent.

[0014] Preferably, the particle distribution characteristics include characteristic particle size and cumulative particle size distribution percentage;

[0015] The cumulative particle size distribution percentage was determined by the characteristic particle size of the lake and reservoir silt-red mud-steel slag modified mixture, blast furnace ore powder, nano-SiO2, cement and lake and reservoir ultrafine sand.

[0016] Preferably, when the maximum particle size of the ultrafine sand does not exceed 150 μm, the composite material obtained according to the formula determined by the system is a repair ECC (jet repair high ductility composite material);

[0017] At this point, the first objective function is: D8-12 (0.68μm), D46-54 (15.25μm) and D89-91 (102.46μm);

[0018] in,

[0019] The same principle applies to the others;

[0020]

[0021] Where q is a coefficient, and D q D represents the particle size of a single raw material in a mixed powder. q min D represents the minimum particle size of the mixed powder. q max The maximum particle size of the mixed powder (the same applies below);

[0022] In the above formula, i represents any one of the following: lake / reservoir silt-red mud-steel slag modified mixture, blast furnace ore powder, nano-SiO2, cement, and lake / reservoir ultrafine sand; x represents the mass percentage of any one raw material in the mixed powder; D represents the particle size of each raw material in the mixed powder; the same applies below.

[0023] The first constraint is:

[0024]

[0025] 40%≤x 超细粉沙 ≤60% wt ;

[0026]

[0027] Preferably, when the maximum particle size of the ultrafine sand does not exceed 300 μm, the composite material obtained according to the formula determined by the system is hydraulic ECC (hydraulic pumping high ductility composite material);

[0028] The first objective function is D8-12 (0.84μm), D46-54 (26.57μm) and D89-91 (201.15μm);

[0029] The first constraint is:

[0030]

[0031] 40%≤x 超细粉沙 ≤60%wt ;

[0032]

[0033] Preferably, the auxiliary agents include water-reducing agents, expanding agents, and modified carbon fibers.

[0034] Preferably, the expanding agent is a type II calcium-magnesium composite expanding agent that meets the requirements of T / CECS10082-2020.

[0035] Preferably, the modified carbon fiber is a recyclable modified carbon fiber obtained by crushing and processing waste aircraft shells and removing resin through high-temperature pyrolysis.

[0036] Preferably, the water-reducing agent includes a high-performance polycarboxylate water-reducing agent; wherein the water-reducing agent needs to be dissolved in water before use, and the mass ratio of the water-reducing agent to water is 1:1.

[0037] Preferably, the basic model of the auxiliary agent is related to the mass of the mixed powder and the volume of the high-ductility composite material;

[0038] The basic model of the adjuvant includes a second objective function and a second constraint condition;

[0039] Wherein, the second objective function is the mass of the mixed powder and the volume of the high-ductility composite material;

[0040] The second constraint is:

[0041] The expanding agent is 2%-4% of the mass of the mixed powder; and / or

[0042] The water-reducing agent is 0.5%-2% of the mass of the mixed powder; and / or

[0043] Modified carbon fiber accounts for 1%-3% of the total volume of the high-ductility composite material.

[0044] The second technical solution of the present invention:

[0045] A method for determining the formulation of a high-ductility composite material based on lake and reservoir sediments, comprising the following steps using the aforementioned system:

[0046] (1) The particle distribution characteristics of the modified mixture of lake silt-red mud-steel slag, blast furnace ore powder, nano SiO2, cement and lake ultrafine sand were obtained using the acquisition module.

[0047] (2) Based on the principle of closest packing, with the goal of maximizing the amount of ultrafine sand, the first determination module is used to determine the optimal formula of the mixed powder;

[0048] (3) Determine the optimized formulation of high ductility composite material using the second determination module and the basic model of the auxiliary agent.

[0049] The third technical solution of this invention:

[0050] A high-ductility composite material based on lake and reservoir sediments, conforming to the optimized formulation of a high-ductility composite material determined by the aforementioned system or method, comprising the following raw materials:

[0051] Modified mixture of lake and reservoir silt, red mud, and steel slag, blast furnace ore powder, nano-SiO2, cement, lake and reservoir ultrafine sand, and auxiliary agents.

[0052] Preferably, the modified mixture of lake and reservoir silt-red mud-steel slag is prepared by mixing lake and reservoir silt, red mud and steel slag in a mass ratio of (4-6):(1-2):(1-2) and then subjecting it to alkali-thermal modification.

[0053] Preferably, the blast furnace ore powder is S95 slag powder, with a specific surface area of ​​not less than 350 m². 2 / kg.

[0054] Preferably, the nano-SiO2 is SF85 grade silicon powder.

[0055] Preferably, the cement is 42.5P·O ordinary Portland cement that meets GB 175-2023.

[0056] Preferably, the ultrafine silt from the lake or reservoir is obtained by further screening of the lake or reservoir sediment after sediment separation, resulting in extremely fine particles with a maximum particle size not exceeding 300 μm or 150 μm, and an apparent bulk density of not less than 2500 kg / m³. 3 The bulk density is not less than 1280 kg / m³ 3 .

[0057] Fourth technical solution of the present invention:

[0058] A method for preparing a highly ductile composite material based on lake and reservoir sediment includes the following steps:

[0059] 1. Obtain the optimized formulation of the high-ductility composite material based on the above-described system or method;

[0060] 2. Weigh each raw material according to the optimized formula and set aside for later use;

[0061] 3. Add the lake and reservoir ultrafine sand, cement, nano-SiO2, lake and reservoir silt-red mud-steel slag modified mixture, and blast furnace ore powder into the mixer in the following order, and stir for 60 seconds to obtain the mixture;

[0062] 4. Add auxiliary agents to the mixture and stir until homogeneous to obtain the high ductility composite material.

[0063] Preferably, step 4 is specifically performed as follows:

[0064] The high-ductility composite material is obtained by adding an expanding agent and modified carbon fiber to the mixture, stirring for 30 seconds, then adding a water-reducing agent and stirring for 60 seconds.

[0065] Preferably, if the prepared high-ductility composite material is a spray-repair high-ductility composite material, the spray pressure after adding the auxiliary agent is 0.8-1.2 MPa;

[0066] The expanding agent is 2%-4% of the mass of the mixed powder;

[0067] The water-reducing agent is 1.0%-1.5% of the mass of the mixed powder;

[0068] The modified carbon fiber accounts for 1%-3% of the total volume of the high-ductility composite material.

[0069] Preferably, if the prepared high-ductility composite material is a high-ductility composite material for hydraulic pumping, the expanding agent is 1%-3% of the mass of the mixed powder;

[0070] The water-reducing agent is 0.5%-2% of the mass of the mixed powder;

[0071] The modified carbon fiber constitutes 2%-2.5% of the total volume of the high-ductility composite material.

[0072] Compared with the prior art, the present invention has the following advantages and technical effects:

[0073] (1) Full-scale utilization of lake and reservoir silt

[0074] The ultrafine silt from lake and reservoir sediments provided by this invention can account for 40% to 60% of the mass of the composite material. Moreover, the silt with high clay content, after being modified by alkali and heat with red mud and steel slag, is used as a cementing material. It is compacted with cement, mineral powder and nano-SiO2 to fill the gaps between ultrafine silt particles. While achieving high density and high strength, it realizes the full-graded resource utilization of sediments and overcomes the global problem of the difficulty in resource utilization of ultrafine particles from lake and reservoir sediments.

[0075] (2) Flexible construction methods

[0076] The lake and reservoir sediment-based composite material provided by this invention is designed for two pouring methods: spray repair and pumping construction of large deformation hydraulic structures. In the design of the composite powder material, the maximum particle size of the ultrafine sand is controlled to not exceed 150μm and 300μm, respectively. Through the design method proposed in this invention, a high-toughness composite powder is obtained, and the incorporation of modified carbon fiber and water-reducing agent is controlled to regulate the construction performance of the mixture. It is suitable for both spray repair and large-flow pumping construction of hydraulic structures, with strong applicability and broad application prospects.

[0077] (3) High degree of greenness and environmental safety

[0078] The high-toughness composite material provided by this invention uses lake and reservoir sediment as the main raw material. For silt containing some heavy metals, through synergistic alkaline-thermal modification with red mud and steel slag, the strong alkali of red mud and the mineral alkali of steel slag can be used to solidify and stabilize the heavy metals, fully utilizing the resource properties of the sediment while ensuring environmental safety. Simultaneously, recycled carbon fibers are obtained by processing and modifying discarded aircraft shells and dispersed in the composite material. Through random distribution, bridging, and energy dispersion, the interfacial bonding between the carbon fibers and cement-based materials is enhanced, improving the strength and toughness of the composite material. This achieves the recycling and substitution of waste materials such as cementitious materials, micro-aggregates, and admixtures, improving the environmental friendliness of the composite material.

[0079] (4) Good processing performance and economy

[0080] The lake and reservoir silt provided by this invention is based on the principle of using local materials. The silt generated from lake and reservoir dredging is directly screened after dewatering. The ultrafine sand is used directly, and the silt is modified and reused. It is combined with watershed solid waste and waste carbon fiber for modification and reuse, avoiding large-scale land occupation and stockpiling of silt. The preparation process of this composite material is similar to that of ordinary cement-based materials. Only the feeding sequence and mixing time need to be adjusted. It has good processing performance and significant economic benefits. Attached Figure Description

[0081] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0082] Figure 1 This is a process flow diagram for preparing a high-ductility composite material based on lake and reservoir sediment according to the present invention;

[0083] Figure 2 XRD pattern of lake and reservoir sediments;

[0084] Figure 3 The compressive strength of the composite material prepared in Example 3;

[0085] Figure 4 The flexural strength is the value of the composite material prepared in Example 3. Detailed Implementation

[0086] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0087] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0088] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0089] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0090] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0091] like Figure 1 As shown, this invention discloses a method for preparing a high-toughness composite material based on lake and reservoir sediment, comprising the following steps:

[0092] S1: Test the particle distribution characteristics of modified mixtures of lake and reservoir silt-red mud-steel slag, blast furnace ore powder, nano-SiO2, ordinary silicate cement and ultrafine sand from lake and reservoir.

[0093] S2: Based on the principle of the densest packing of powders, and with the goal of maximizing the content of ultrafine sand, constraints are set for two pouring methods: spray repair and hydraulic pumping construction.

[0094] ①The cumulative particle size distribution percentage corresponding to the characteristic particle size of the mixed powder must be within the control index range, see Table 1 and Table 2;

[0095] Table 1. Control Indicators of Powder Characteristics for High-Ductility Composite Materials Used in Jetting Repair with Ultrafine Sand from Lakes and Reservoirs

[0096] index <![CDATA[P 0.68μm ]]> <![CDATA[P 15.25μm ]]> <![CDATA[P 102.46μm ]]> mica mud content Most compact value 0.1 0.5 0.9 2 1 Control range 0.08～0.12 0.46～0.54 0.89～0.91 ＜2％ ＜2％

[0097] Table 2. Characteristic values ​​control indicators for ultrafine silt from lakes and reservoirs used in hydraulic pumping of high-ductility composite material powders.

[0098] index <![CDATA[P 0.84μm ]]> <![CDATA[P 26.57μm ]]> <![CDATA[P 201.15μm ]]> mica mud content Most compact value 0.1 0.5 0.9 2 1 Control range 0.08～0.12 0.46～0.54 0.89～0.91 ＜2％ ＜2％

[0099] ② When used for preparing high-ductility composite materials for hydraulic pumping construction, the total mass ratio of adhesive material should not be less than 40%; when used for preparing high-ductility repair composite materials for spraying construction, the total mass ratio of adhesive material should not be less than 50%; the adhesive material should contain a modified mixture of lake and reservoir silt-red mud-steel slag, blast furnace ore powder, nano-SiO2, and ordinary silicate cement ultrafine particle powder materials, which are used to fill the voids between lake and reservoir ultrafine sand particles and generate sufficient cementitious hydration products to form a whole;

[0100] ③ The mass percentage of ultrafine silt in lakes and reservoirs shall not be less than 40% and shall not exceed 60%;

[0101] ④ The raw material composition is expressed as a percentage, and the sum of all raw materials is normalized to 1.

[0102] The above constraints:

[0103]

[0104] S3: Weigh the powder material according to the mass ratio of each raw material in the mixed powder determined in step (1) above. Weigh the calcium-magnesium composite expansion agent according to 2%-4% of the mass of the mixed powder material. Weigh the high-performance water-reducing agent and an appropriate amount of water according to 0.5%-2% of the mass of the mixed powder material. Dissolve the high-performance water-reducing agent in water for later use (the mass ratio of water-reducing agent to water is 1:1). Weigh the modified carbon fiber according to 1%-3% of the total volume of the high-ductility composite material.

[0105] S4: Add the following ingredients to the mixer in the following order: ultrafine sand from the lake / reservoir, ordinary silicate cement, nano-SiO2, modified mixture of lake / reservoir silt-red mud-steel slag, and blast furnace ore powder. Mix for 60 seconds, then add calcium-magnesium composite expansion agent and modified carbon fiber. Continue mixing for 30 seconds, then add water-reducing agent and continue mixing for 60 seconds. This will produce a high-ductility composite material for spraying or pumping construction.

[0106] In some preferred embodiments, the preparation method of the modified mixture of lake and reservoir silt-red mud-steel slag in step S1 includes the following steps:

[0107] Lake silt, red mud, and steel slag are mixed evenly at a mass ratio of (4-6):(1-2):(1-2); the mixed material is then subjected to medium-temperature calcination and alkaline-thermal modification at a temperature of 200-300℃. The specific steps are as follows:

[0108] Weigh out lake and reservoir silt, red mud and steel slag according to the mass ratio (4-6):(1-2):(1-2) and mix them thoroughly;

[0109] Place the mixture in an oven and dry it at 60-100℃ to remove excess moisture and ensure that the material is dried evenly.

[0110] Place the dried mixture into a high-temperature furnace, set the temperature to 200-300℃, control the calcination time to 2-3 hours, and then allow it to cool naturally.

[0111] Add 1.0 mol / L sodium hydroxide to the cooled mixture at a mass ratio of (mixture:sodium hydroxide) = (10:1), mix thoroughly, reheat to 100-200℃, maintain for 1 hour, then cool the alkali-heat modified material to room temperature and grind it to a specific surface area of ​​not less than 500 m². 2 / kg of modified mixture of lake and reservoir silt, red mud and steel slag.

[0112] In some preferred embodiments, the preparation process of the modified carbon fiber in step S3 is as follows:

[0113] After screening and cleaning, the carbon fiber composite material from the waste aircraft shell is cut, crushed and ground to obtain short fiber carbon fiber and resin powder with a length of 10-30mm.

[0114] Modified carbon fibers are prepared by immersing short fibrous carbon fibers in a 1.0 mol / L NaOH solution, stirring for 30 minutes, removing them and drying them in an oven at 105℃.

[0115] In addition, the present invention also discloses a high-toughness composite material based on lake and reservoir silt prepared by the above preparation method.

[0116] This invention provides a high-ductility composite material based on lake and reservoir sediment and its preparation method. The material uses lake and reservoir sediment as the main raw material, with ultrafine sand replacing standard quartz sand as aggregate. The composite material is designed with the goal of maximizing the ultrafine sand content. Utilizing the strong alkalinity of red mud, a characteristic solid waste from the Yangtze River basin, and the inherent mineral alkali properties of steel slag, high-clay-content silt is used in combination with red mud and steel slag for alkali-thermal modification as a cementing material. The XRD patterns of the lake and reservoir silt before and after alkali-thermal conversion are shown in the figure below. Figure 2 As shown in the figure, this invention achieves the synergistic alkaline-thermal modification and resource utilization of silt, red mud, and steel slag within the watershed. Furthermore, this invention innovatively utilizes modified carbon fibers obtained from the processing and modification of discarded aircraft shells. By leveraging the random distribution of carbon fibers in the cementation system and their bridging and energy transfer effects under load, it achieves excellent reinforcement and toughening effects. The high-ductility composite material prepared based on this method not only enables the full-gradation use of silt deposits in onshore lakes and reservoirs but also achieves the synergistic treatment and resource utilization of multiple solid wastes. This results in products with high strength, high toughness, crack resistance, and other technical advantages, and with broad application prospects.

[0117] Unless otherwise specified, "room temperature" in this invention refers to 20-30℃.

[0118] All raw materials used in this invention were purchased from the market.

[0119] The technical solution of the present invention will be further illustrated by the following embodiments.

[0120] Example 1

[0121] A system for determining the formulation of high-ductility composite materials based on lake and reservoir sediments, comprising:

[0122] The acquisition module obtains the particle distribution characteristics (characteristic particle size and cumulative particle size distribution percentage) of the modified mixture of lake silt-red mud-steel slag, blast furnace ore powder, nano-SiO2, cement, and lake ultrafine sand; among which, the corresponding cumulative particle size distribution percentage is determined by the characteristic particle size of the modified mixture of lake silt-red mud-steel slag, blast furnace ore powder, nano-SiO2, cement, and lake ultrafine sand.

[0123] The first determination module, with the maximum amount of ultrafine sand from lakes and reservoirs as the target, is used to determine the formula optimization model of the mixed powder (composed of five raw materials) based on the obtained particle distribution characteristics of the modified mixture of lake silt-red mud-steel slag, blast furnace ore powder, nano SiO2, cement and ultrafine sand from lakes and reservoirs.

[0124] The formulation optimization model for the mixed powder includes a first objective function and a first constraint condition;

[0125] (i) When the maximum particle size of ultrafine sand does not exceed 150 μm, the composite material obtained according to the formula determined by the system is spray repair ECC (spray repair high ductility composite material);

[0126] At this point, the first objective function is: D8-12 (0.68μm), D46-54 (15.25μm) and D89-91 (102.46μm);

[0127] in,

[0128] The same principle applies to the others;

[0129] In the above formula, i represents any one of the following: modified mixture of lake / reservoir silt-red mud-steel slag, blast furnace ore powder, nano-SiO2, cement, and lake / reservoir ultrafine sand; x represents the mass percentage of any one raw material in the mixed powder; P represents... D represents the particle size of each raw material in the mixed powder; the same applies below.

[0130] The first constraint is:

[0131]

[0132] 40%≤x 超细粉沙 ≤60% wt ;

[0133]

[0134] (ii) When the maximum particle size of ultrafine sand does not exceed 300μm, the composite material obtained according to the formula determined by the system is hydraulic pumping ECC (hydraulic pumping high ductility composite material).

[0135] The first objective functions are D8-12 (0.84μm), D46-54 (26.57μm) and D89-91 (201.15μm);

[0136] The first constraint is:

[0137]

[0138] 40%≤x 超细粉沙 ≤60% wt ;

[0139]

[0140] The second determining module is used to determine the formulation of the high-ductility composite material based on the formulation optimization model of the mixed powder and the basic model of the auxiliary agents (including water-reducing agents, expanding agents and modified carbon fibers);

[0141] The basic model for the additives is related to the mass of the mixed powder and the volume of the high-ductility composite material;

[0142] The basic model of the adjuvant includes a second objective function and a second constraint.

[0143] The second objective function is the mass of the mixed powder and the volume of the high-ductility composite material;

[0144] The second constraint is:

[0145] The expanding agent is 2%-4% of the mass of the mixed powder;

[0146] The water-reducing agent is 0.5%-2% of the mass of the mixed powder;

[0147] Modified carbon fiber accounts for 1%-3% of the total volume of the high-ductility composite material.

[0148] Example 2

[0149] A method for determining the formulation of a high-ductility composite material based on lake and reservoir sediments, using the determination system described in Example 1, comprises the following steps:

[0150] (1) The particle distribution characteristics of the modified mixture of lake silt-red mud-steel slag, blast furnace ore powder, nano SiO2, cement and lake ultrafine sand were obtained using the acquisition module.

[0151] (2) Based on the principle of closest packing, with the goal of maximizing the amount of ultrafine sand, the first determination module is used to determine the optimal formula of the mixed powder;

[0152] (3) Determine the optimized formulation of high ductility composite material using the second determination module and the basic model of the auxiliary agent.

[0153] Example 3 (Spray Repair of High-Ductility Composite Materials)

[0154] A method for preparing a high-toughness composite material based on lake and reservoir sediment includes the following steps:

[0155] S1: Obtain silt from the Three Gorges Reservoir area. Mix the silt, red mud, and steel slag evenly in a mass ratio of 6:2:2. Place the mixture in an oven and dry it at 80℃ to remove excess moisture and ensure uniform drying. Place the dried mixture in a high-temperature furnace, set the temperature to 300℃, and control the calcination time for 2 hours, then allow it to cool naturally. Add 1.0 mol / L sodium hydroxide to the cooled mixture at a mass ratio of (mixture:sodium hydroxide) = (10:1), mix thoroughly, reheat to 150℃, maintain for 1 hour, and then cool the alkali-heat modified material to room temperature before grinding it to a specific surface area of ​​not less than 500 m². 2 / kg of modified mixture of lake and reservoir silt, red mud and steel slag;

[0156] S2: Test the particle distribution characteristics of modified mixtures of lake and reservoir silt-red mud-steel slag, blast furnace ore powder, nano-SiO2, ordinary silicate cement and ultrafine sand from lakes and reservoirs;

[0157] S3: Based on the principle of the densest packing of powders, with the goal of maximizing the content of ultrafine sand, for the spray repair pouring method, the characteristic value control index of ultrafine sand from lakes and reservoirs for spray repair of high ductility composite material powder is set, as detailed in Table 1.

[0158] Based on the indicators, the modified mixture of lake silt, red mud, and steel slag contains 10%, blast furnace ore powder 25%, nano-SiO2 10%, and ordinary silicate cement 55%. This mixture is collectively referred to as the cementing material. The mass ratio of the cementing material to the ultrafine sand from the lake / reservoir is 55:45.

[0159] S4: The preparation and modification method of waste carbon fiber includes: screening and cleaning the carbon fiber composite material of waste aircraft shell, cutting, crushing and grinding it to obtain short fiber carbon fiber with a length of 20 mm and resin powder; immersing the short fiber carbon fiber in a 1.0 mol / L NaOH solution, stirring for 30 min, taking it out and drying it in an oven at 105℃ to obtain recycled carbon fiber.

[0160] S5: Weigh 2% of the mass of the mixed powder material, take 1.5% of the mass of the mixed powder material, take 1.5% of the mass of the high-performance water-reducing agent and an appropriate amount of water, dissolve the high-performance water-reducing agent in water (wherein the mass ratio of water-reducing agent to water is 1:1) for later use, and weigh 2% of the total volume of the high-ductility composite material, take waste modified carbon fiber.

[0161] S6: Add the following ingredients to the mixer in the following order: ultrafine sand from the lake / reservoir, ordinary silicate cement, nano-SiO2, modified mixture of lake / reservoir silt-red mud-steel slag, and blast furnace ore powder. Mix for 60 seconds. Then add calcium-magnesium composite expanding agent and waste carbon fiber, and continue mixing for 30 seconds. Add water-reducing agent and continue mixing for 60 seconds. Perform spraying at a pressure of 1 MPa. This will produce a high-ductility composite material for spraying construction.

[0162] S7: Compressive and flexural strength tests were conducted according to the relevant provisions of JC / T 2381-2016 "Repair Mortar". Specimens were cured under standard conditions. Flexural strength tests were performed on 40mm×40mm×160mm prism specimens, and compressive strength tests were performed on cubes with a side length of 40mm. Test results are as follows: Figure 3 and Figure 4 As shown.

[0163] Example 4 (High-ductility composite material for hydraulic pumping)

[0164] The difference from Example 3 is that,

[0165] S3, for hydraulic pumping and pouring methods, sets the characteristic value control index of ultrafine sand from lakes and reservoirs for high ductility composite material powder used in hydraulic pumping, see Table 2 for details;

[0166] Based on the indicators, the modified mixture of lake and reservoir silt-red mud-steel slag contains 15%, blast furnace ore powder 28%, nano-SiO2 7%, and ordinary Portland cement 50%. The above raw materials are collectively referred to as cementing materials. The mass ratio of cementing materials to ultrafine lake and reservoir sand is 40:60.

[0167] S5. Weigh calcium-magnesium composite expansion agent at 1.5% of the mass of the mixed powder material, weigh high-performance water-reducing agent and appropriate amount of water at 2% of the mass of the mixed powder material, dissolve the high-performance water-reducing agent in water (wherein, the mass ratio of water-reducing agent to water is 1:1) for later use, and weigh waste modified carbon fiber at 2% of the total volume of the high ductility composite material.

[0168] S6, no spraying step is performed.

[0169] The other steps and conditions are the same as in Example 3.

[0170] The compressive strength of the hydraulic pumping high-ductility composite material prepared in this embodiment is 37.2 MPa (3d), 72.6 MPa (7d), and 94.5 MPa (28d); the flexural strength is 9.1 MPa (3d), 11.8 MPa (7d), and 13.2 MPa (28d). The test standards and conditions are the same as in Example 3.

[0171] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A system for determining the formulation of high-ductility composite materials based on lake and reservoir sediments, characterized in that, include: The acquisition module acquires the particle distribution characteristics of modified mixtures of lake and reservoir silt-red mud-steel slag, blast furnace ore powder, nano-SiO2, cement, and lake and reservoir ultrafine sand. The first determination module, with the maximum amount of ultrafine sand from lakes and reservoirs as the target, is used to determine the formulation optimization model of the mixed powder based on the obtained particle distribution characteristics of the lake and reservoir silt-red mud-steel slag modified mixture, blast furnace ore powder, nano SiO2, cement and ultrafine sand from lakes and reservoirs. The formulation optimization model for the mixed powder includes a first objective function and a first constraint condition; When the maximum particle size of ultrafine silt in lakes and reservoirs does not exceed 150 μm, the composite material obtained according to the formula determined by this system is used as a high-ductility composite material for spray repair. The first objective function is: D8-12 (0.68μm), D46-54 (15.25μm) and D89-91 (102.46μm); Where, D8-12 (0.68μm) = ; D46-54(15.25μm)= ; D89-91(102.46μm)= ; ； Where q is a coefficient, and D q D represents the particle size of a single raw material in a mixed powder. q min D represents the minimum particle size of the mixed powder. q max The maximum particle size of the mixed powder; The first constraint is: ； ； ； In the above formula, i represents any one of the following: lake silt-red mud-steel slag modified mixture, blast furnace ore powder, nano-SiO2, cement, and lake ultrafine sand; x represents the mass percentage of any one raw material in the mixed powder; and D represents the particle size of each raw material in the mixed powder. When the maximum particle size of ultrafine silt in lakes and reservoirs does not exceed 300 μm, the composite material obtained according to the formula determined by this system is a high-ductility composite material for hydraulic pumping. The first objective function is D8-12 (0.84μm), D46-54 (26.57μm) and D89-91 (201.15μm); Where, D8-12 (0.84μm) = ; D46-54(26.57μm)= ; D89-91(201.15μm)= ; The first constraint is: ； ； ； In the above formula, i represents any one of the following: lake silt-red mud-steel slag modified mixture, blast furnace ore powder, nano-SiO2, cement, and lake ultrafine sand; x represents the mass percentage of any one raw material in the mixed powder; and D represents the particle size of each raw material in the mixed powder. The second determining module is used to determine the formulation of the high-ductility composite material based on the formulation optimization model of the mixed powder and the basic model of the auxiliary agent; The auxiliary agents include one or more of water-reducing agents, expanding agents, and modified carbon fibers; The basic model of the adjuvant includes a second objective function and a second constraint condition; Wherein, the second objective function is the mass of the mixed powder and the volume of the high-ductility composite material; The second constraint is: The amount of expanding agent added is 2%-4% of the mass of the mixed powder; and / or The water-reducing agent is added at a rate of 0.5%-2% of the mass of the mixed powder; and / or The amount of modified carbon fiber added is 1%-3% of the total volume of the high-ductility composite material.

2. The system for determining the formulation of a high-ductility composite material based on lake and reservoir sediments according to claim 1, characterized in that, The particle distribution characteristics include characteristic particle size and cumulative particle size distribution percentage; The cumulative particle size distribution percentage was determined by the characteristic particle size of the lake and reservoir silt-red mud-steel slag modified mixture, blast furnace ore powder, nano-SiO2, cement and lake and reservoir ultrafine sand.

3. A method for determining the formulation of a high-ductility composite material based on lake and reservoir sediment, characterized in that, The following steps are performed using the determining system according to any one of claims 1-2: (1) The particle distribution characteristics of the modified mixture of lake silt-red mud-steel slag, blast furnace ore powder, nano SiO2, cement and lake ultrafine sand were obtained by using the acquisition module; (2) Based on the principle of closest packing, with the goal of maximizing the amount of ultrafine sand, the optimal formula of the mixed powder is determined using the first determination module; (3) Determine the formulation of high ductility composite material using the second determination module and the basic model of the auxiliary agent.

4. A high-ductility composite material based on lake and reservoir sediment, characterized in that, Including the following raw materials: Modified mixture of lake and reservoir silt, red mud, and steel slag, blast furnace ore powder, nano-SiO2, cement, ultrafine sand from lakes and reservoirs, and auxiliary agents; The amount of each raw material used conforms to the formulation of the high-ductility composite material determined by the determination system described in any one of claims 1-2 or the determination method described in claim 3.

5. A high-ductility composite material based on lake and reservoir sediment according to claim 4, characterized in that, The modified mixture of lake and reservoir silt-red mud-steel slag is prepared by mixing lake and reservoir silt, red mud and steel slag in a mass ratio of (4-6):(1-2):(1-2) and then calcining at high temperature and modifying with alkaline heat.

6. A method for preparing a high-ductility composite material based on lake / reservoir sediment, characterized in that, Includes the following steps: The raw material ratio of the high-ductility composite material is obtained by the determining system according to any one of claims 1-2 or the determining method according to claim 3; Weigh each ingredient according to the specified proportions and set aside. The mixture is added to the mixer in the following order: ultrafine sand from the lake / reservoir, cement, nano-SiO2, modified mixture of lake / reservoir silt-red mud-steel slag, and blast furnace ore powder. The mixture is stirred until homogeneous to obtain the final product. Adding an auxiliary agent to the mixture and stirring until homogeneous yields the high-ductility composite material.

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