Solid-waste-based Yellow River sediment cementing material and preparation method of artificial flood prevention preparation stone

Abstract

The invention relates to the technical field of building materials, in particular to a solid-waste-based Yellow River sediment cementing material and a preparation method of an artificial flood prevention preparation stone. The solid waste-based Yellow River sediment cementing material is prepared from the following raw materials in parts by weight: 300 to 500 parts of Yellow River sediment, 80 to 130 parts of furnace slag ash, 40 to 80 parts of steel slag, 20 to 50 parts of alunite tailings, 25 to 55 parts of mirabilite gypsum, 0.5 to 1.5 parts of crack self-repairing material and 1 to 3 parts of workability regulator. The artificial flood prevention prepared stone prepared by the method has excellent mechanical properties and erosion resistance, can reduce carbon emission and improve the ecological property, and realizes resource utilization of the Yellow River silt.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a preparation method of a solid waste-based Yellow River sediment cementitious material and an artificial flood prevention stone. Background Art

[0002] The Yellow River is the second largest river in my country and is known for its "good siltation, good flooding, and good migration". The flood control task of the Yellow River is arduous and the responsibility is heavy. With the progress of society, people have higher and higher requirements for rapid rescue and improving rescue effects. Every year, the amount of riprap used for rescue in the Yellow River is hundreds of thousands of cubic meters. Since stone is a non-renewable resource, the purchase price of the prepared stone used for flood control and rescue has been rising year by year. The cost of using stone as prepared stone is high, and it also causes a waste of resources. Traditional prepared stone is limited by construction conditions and materials. The root stone of the dam buttress bank protection cannot meet the anti-scouring requirements due to its low strength and poor density. It is very easy to get lost under the scouring of water flow, which significantly reduces the stability of the dam bank. The loss rate of root stone in the Yellow River rescue is about 20-30%.

[0003] Based on this, the present invention is devoted to the research of solid waste-based Yellow River silt cementitious materials and artificial flood prevention and prevention stones.

[0004] The Yellow River sediment has certain volcanic ash activity. The Yellow River sediment with silicon and aluminum components such as SiO2, Al2O3, and Fe2O3 as the basic raw material has great utilization value and broad application prospects. The present invention improves the activity index by classifying and multi-modifying the Yellow River sediment; further synergistically utilizes solid wastes such as slag ash generated by power generation, steel slag generated by steelmaking, and thenardite gypsum generated by calcium glauberite extraction to prepare curing agents, solidify the inert coarse aggregate in the Yellow River sediment, and is expected to produce ecological sinter-free flood prevention and prevention stones. Summary of the invention

[0005] The present invention provides a method for preparing a solid waste-based Yellow River silt cementitious material and an artificial flood control and prevention stone. The prepared artificial flood control and prevention stone has excellent mechanical properties and erosion resistance, can reduce carbon emissions and improve ecology, solves the urgent needs of Yellow River flood control and the limitations of natural stones in the prior art, and realizes the resource utilization of Yellow River silt.

[0006] One of the technical solutions adopted by the present invention is: Provided is a solid waste-based Yellow River silt cementitious material, comprising the following raw materials in parts by weight: 300-500 parts of Yellow River silt, 80-130 parts of slag ash, 40-80 parts of steel slag, 20-50 parts of alum stone tailings, 25-55 parts of mirabilite gypsum, 0.5-1.5 parts of crack self-repairing material, and 1-3 parts of a workability regulator.

[0007] Furthermore, the Yellow River silt includes coarse silt, fine silt and medium-sized silt; the particle size of coarse silt is ≥150μm, the particle size of fine silt is ≤75μm, and the particle size of medium-sized silt is 75-150μm.

[0008] Furthermore, when preparing artificial flood prevention stones, the coarse sediment is used as aggregate, the fine sediment is used as filling material, and the medium-sized sediment is subjected to activation modification treatment, which can stimulate the sediment activity index and improve the physical structure of the clay component.

[0009] Furthermore, the weight ratio of the coarse sediment, fine sediment and medium-sized sediment is 1:1:1.

[0010] Furthermore, the medium-grained sediment accounts for 45% of the total weight of the Yellow River sediment; the coarse sediment and fine sediment are in equal weight ratios.

[0011] Furthermore, the crack self-repairing material is a modified highly absorbent resin self-repairing liquid, which is prepared as follows: Add 50 parts of SAP particles, 5-7 parts of sodium ethylenediaminetetramethylenephosphonate, 3-5 parts of calcium nitrate, 3-5 parts of sodium silicate, 0.5-1.5 parts of triisopropanolamine and 100-120 parts of deionized water into a magnetic stirrer and stir for 15-20 minutes to obtain the product.

[0012] Furthermore, the modified super absorbent resin self-repairing fluid quickly turns into a gel-like substance after absorbing water, and has a high water-retaining effect. As the free water in the pores decreases, the water is slowly released. The calcium and silicon in the modified super absorbent resin are continuously dissolved, ensuring the subsequent hydration reaction, generating a large amount of hydration products to fill the pores and prevent the invasion of harmful substances.

[0013] Furthermore, the workability regulator comprises a water reducing component, an antifreeze component and a permeable waterproof component, and the weight ratio of the three components is 3-5:6-9:0.5-2. The three components are weighed according to the specified mass and mixed evenly to obtain the workability regulator.

[0014] Furthermore, the water-reducing component is one or more of polycyclic aromatic sulfonate water-reducing agent, melamine resin water-reducing agent, coumarone resin water-reducing agent, sucrose calcium water-reducing agent, and aliphatic hydroxy sulfonate water-reducing agent; the antifreeze component is one or more of sodium chloride, sodium nitrite, sodium dichromate alkylbenzene sulfonate, alkylphenol ethylene oxide condensate, and fatty alcohol sodium sulfate; the penetration waterproofing component is one or more of triethanolamine, sodium methyl silicate, sodium ethyl silicate, methyltriethoxysilane, and n-propyltrimethoxysilane.

[0015] Furthermore, the water-reducing component is a combination of coumarone resin water-reducing agent, sucrose calcium series water-reducing agent, and aliphatic hydroxysulfonate series water-reducing agent, in a ratio of 0.5:0.5:2; the antifreeze component is a combination of sodium nitrite, sodium dichromate alkylbenzene sulfonate, and alkylphenol ethylene oxide condensate, in a ratio of 0.5:0.5:3; the penetration waterproofing component is a combination of sodium methyl silicate, sodium ethyl silicate, and methyltriethoxysilane, in a ratio of 1:1:0.5.

[0016] Furthermore, the alunite tailings used in the above-mentioned solid waste-based Yellow River sediment cementitious material contain a large amount of quartz and mica, which can provide active silicon for the formation of aluminosilicate gel and calcium aluminite; the power plant slag ash contains a large amount of mullite, quicklime, and feldspar minerals, which can provide sufficient active calcium for the hydration reaction and ensure the long-term stability of the structure; the steel slag contains a large amount of amorphous dicalcium silicate, tricalcium silicate, and free calcium oxide, which can ensure the early strength while adjusting the pH value of the system, promote the rupture of Si-O and Al-O bonds on the surface of materials such as the Yellow River sediment and slag ash, and release active SiO4 4 ⁻ and AlO4 5 ⁻ ions react with Ca(OH)2 to form gelling hydration products, such as calcium silicate hydrate (CSH) gel and calcium aluminate hydrate (CAH), with the chemical formula as follows. The gel fills the pores, refines the pore size distribution, and improves the density and mechanical properties.

[0017] Ca(OH)2+SiO2+H2O→CaO·SiO2·H2O(CSH) Ca(OH)2+Al2O3+H2O→CaO·Al2O3·H2O(CAH) The volcanic ash reaction of the solid waste-based Yellow River silt cement material with the above mineral admixtures is slow and continuous. The CSH gel generated in the later stage can partially compensate for the volume deformation caused by the early hydration shrinkage. At the same time, the formation of gel-like substances reduces the capillary volume, reduces the water evaporation channel, inhibits volume shrinkage, prevents cracks, and improves volume stability.

[0018] Glauber's salt gypsum can ensure the sulfate ion concentration of the hydration system and promote the formation of ettringite. The above-mentioned various solid wastes work synergistically and stimulate each other to generate a large number of gel minerals and ettringite crystals, which improve the density of the system, ensure the mechanical properties of flood control and prevention stones, and improve their durability.

[0019] Furthermore, the specific surface area of ​​the Yellow River sediment is 50-150㎡ / kg, and the cumulative content of CaO and SiO2 is ≥60%; the specific surface area of ​​steel slag is 310-390㎡ / kg, and the cumulative content of CaO, SiO2 and Al2O3 is 60-75%; the specific surface area of ​​alunite tailings is 220-280㎡ / kg, the CaO content is ≥40%, and the potassium aluminum sulfate content is 0.5-3%; the calcium sulfate content of Glauber's salt gypsum is ≥85%, and the sodium sulfate content is ≥2%.

[0020] The second technical solution adopted by the present invention is: A method for preparing an artificial flood prevention stone is provided, which is prepared by using the above solid waste-based Yellow River silt cement material, and comprises the following steps: Step 1: The original mixed Yellow River sediment is screened into three particle sizes: fine sediment ≤75μm, medium-sized sediment 75-150μm, and coarse sediment ≥150μm for later use; Step 2: Mix the medium-sized sediment and alum stone tailings, crush them to a specific surface area of ​​300-400 m2 / kg, then mix them with fine sediment, and further crush them to 650-750 m2 / kg to obtain cementitious material A; Step 3: Evenly mix the adhesive material A with the slag ash and steel slag; adjust the microwave power to 650-700W, the time to 5-7min, the frequency to 2.4GHz, and nitrogen protection to perform microwave radiation modification to further activate the material to obtain the adhesive material B, which is then mixed with Glauber's salt gypsum, crack self-repairing material and workability regulator to obtain the adhesive material C; Step 4: Mix and stir the cementing material C, coarse mud and water in a weight ratio of 1:2-5:0.25-0.4, fill them into the flood prevention stone mold, naturally cure for 12 hours, and demould to obtain the artificial flood prevention stone.

[0021] Furthermore, in step one, the original mixed Yellow River silt is dried and crushed before screening, the drying is performed by heat pump drying, and the crushing is performed by a jaw crusher.

[0022] Furthermore, in step 2, the ultra-fine airflow pulverizer is used for step-by-step pulverization. The ultra-fine airflow pulverizer does not use chemical solvents in the pulverization process and has a certain compression capacity, which can achieve green environmental protection and high efficiency and energy saving. The grading and step-by-step pulverization process improves the grinding efficiency and saves energy consumption in the grinding process.

[0023] Beneficial effects of the present invention: 1. Compared with the traditional silicate cement which needs to go through two grinding and one burning process from raw materials to finished cement products, which not only consumes a lot of resources and energy, but also emits a lot of carbon dioxide, the solid waste-based Yellow River sediment cementitious materials of the present invention are all composed of solid waste, which improves the utilization rate of solid waste, reduces its harm to the environment, and increases the added value. The preparation process of the cementitious materials of the present invention does not require high-temperature calcination, saves a lot of coal and electricity energy, has a simple preparation process, low carbon emissions, and has high economic value and environmental protection value.

[0024] 2. The cementing material of the present invention has high early strength of flood control and prevention stones prepared through the synergy of multiple components of solid waste and early stimulation of mirabilite gypsum. The 12h strength can reach 30% of the 28d strength. It can be quickly demolded and quickly put into flood control and rescue, thereby improving the mold turnover rate, reducing the site storage cost, maximizing the flood control and prevention stone effect, and having a high engineering application value.

[0025] 3. The excess alunite in the alunite tailings of the cementing material of the present invention can aggregate the clay particles in the Yellow River sediment, and the microwave radiation modification further modifies and strengthens the aggregated particles, reducing the weakening effect of the clay particles in the Yellow River sediment on the mechanical properties and the adsorption effect on the admixture. Under the effect of the crack self-repairing material, the workability adjustment material and the grading effect of the solid waste material, the flood control and prevention stone has a high density, can face various extreme environments during the application process, has good component durability, and avoids the occurrence of degradation and failure problems.

[0026] 4. The invention uses fine-grained Yellow River sediment and multiple solid wastes to replace silicate cement to consolidate coarse-grained Yellow River sediment to prepare sinter-free flood prevention stones with excellent mechanical properties, freeze-thaw resistance, dry-wet cycle resistance, carbonization resistance, etc., which can turn waste into treasure, eliminate hidden dangers, and have huge resource benefits, environmental benefits, ecological benefits, economic benefits, and social benefits. This research not only helps to solve practical problems in the Yellow River flood control, but also provides new ideas and methods for the comprehensive utilization of Yellow River sediment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the microscopic morphology of the flood prevention and stone maintenance of the present invention for 28 days.

[0028] in, Figure 1 (a), (b), and (c) are flood prevention stones prepared in Example 1, Example 3, and Comparative Example 6, respectively. DETAILED DESCRIPTION

[0029] In order to clearly illustrate the technical features of this solution, the present invention is described in detail below through specific implementation methods and in combination with the accompanying drawings. In the embodiments of the present invention, unless otherwise specified, all parts and percentages are weight units, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The experimental methods, detection methods, etc. involved in the following embodiments, unless otherwise specified, are all conventional experimental methods, detection methods, etc. in the prior art. The following is a detailed description.

[0030] The original mixed Yellow River silt used in the embodiment of the present invention is selected from the silt on the bank of the Yellow River in Dongying section.

[0031] Example 1 The raw materials and weight proportions of the solid waste-based Yellow River sediment cementitious material are as follows: 300 parts of Yellow River silt, 80 parts of power plant slag ash, 40 parts of steel plant slag, 20 parts of alum stone tailings, 25 parts of mirabilite gypsum, 0.5 parts of crack self-repairing material, and 1 part of workability regulator.

[0032] The above Yellow River silt is obtained by screening the original mixed Yellow River silt into fine sand ≤75μm: 100 parts, medium sand 75-150μm: 100 parts, and coarse sand ≥150μm: 100 parts, and weighing.

[0033] The preparation steps are as follows: Step 1, drying the original mixed Yellow River silt by heat pump drying process, crushing it evenly by jaw crusher, screening it into three particle sizes, and taking the three particle sizes with equal weight; mixing the medium-sized Yellow River silt with alum stone tailings, using ultra-fine air flow mill to air flow crush it to a specific surface area of ​​350㎡ / kg, and then mixing it with the fine-sized Yellow River silt of ≤75μm, and further crushing it to 650㎡ / kg; obtaining the cementitious material A; Step 2, microwave modification, parameters: 650W, 6 minutes, nitrogen protection; mix the adhesive material A with slag ash and steel slag, perform microwave radiation modification according to the above parameters, and activate to obtain the adhesive material B; set aside; Step 3, preparation of modified super absorbent resin self-repairing liquid: add 50 parts of SAP particles, 5 parts of sodium ethylenediaminetetramethylenephosphonate, 3 parts of calcium nitrate, 3 parts of sodium silicate, 1 part of triisopropanolamine, and 150 parts of deionized water into a magnetic stirrer and stir for 15 minutes to obtain; Step 4, prepare a working property regulator, and mix them evenly according to the weight ratio of water-reducing component: antifreeze component: penetration waterproof component = 3:9:0.5; wherein the water-reducing component is a combination of polycyclic aromatic sulfonate water-reducing agent and melamine resin water-reducing agent in a ratio of 1:2; the antifreeze component is a combination of sodium chloride, sodium dichromate, sodium alkylbenzene sulfonate, and alkylphenol ethylene oxide condensate in a ratio of 1:0.5:3; the penetration waterproof component is a combination of triethanolamine, sodium ethyl silicate, and n-propyltrimethoxysilane in a ratio of 0.2:2:1.

[0034] Step 5, mixing the adhesive material B obtained in step 2, the modified super absorbent resin self-repairing liquid obtained in step 3 and the working property regulator in step 4 to obtain an adhesive material C; Step 6: Mix the cementing material C, coarse silt (≥150 μm) and water in a ratio of 1:3:0.3, fill them into a flood prevention stone mold, naturally cure for 12 hours, and demold to obtain an artificial flood prevention stone.

[0035] Example 2 The raw materials and weight proportions of the solid waste-based Yellow River sediment cementitious material are as follows: 500 parts of Yellow River silt, 130 parts of power plant slag ash, 80 parts of steel plant slag, 50 parts of alum stone tailings, 55 parts of mirabilite gypsum, 1.5 parts of crack self-repairing material, and 3 parts of workability regulator.

[0036] The above Yellow River silt is obtained by screening the original mixed Yellow River silt and weighing it according to weight proportions of fine sand ≤75μm, medium sand 75-150μm, and coarse sand ≥150μm.

[0037] The preparation steps are as follows: Step 1, drying the original mixed Yellow River silt by heat pump drying process, crushing it evenly by jaw crusher, screening it into three particle sizes, and taking the three particle sizes with equal weight; the medium-sized Yellow River silt and alum stone tailings are mixed by air flow to a specific surface area of ​​400㎡ / kg, and then mixed with the fine-sized Yellow River silt of ≤75μm, and further crushed to 700㎡ / kg; to obtain cementitious material A; Step 2, microwave modification, parameters: 700W, 5 minutes, nitrogen protection; mix the adhesive material A with slag ash and steel slag, perform microwave radiation modification according to the above parameters, and activate to obtain the adhesive material B; set aside; Step 3, preparation of modified super absorbent resin self-repairing liquid: 50 parts of SAP particles, 6 parts of sodium ethylenediaminetetramethylenephosphonate, 4 parts of calcium nitrate, 3 parts of sodium silicate, 0.5 parts of triisopropanolamine, and 100 parts of deionized water are added into a magnetic stirrer and stirred for 15 minutes to obtain; Step 4, prepare a working property regulator, and mix and prepare the water-reducing component: antifreeze component: penetration waterproof component in a weight ratio of 5:6:1; wherein the water-reducing component is a combination of coumarone resin water-reducing agent and sucrose calcium water-reducing agent in a ratio of 0.5:2; the antifreeze component is a combination of sodium chloride, alkylphenol ethylene oxide condensate, and sodium fatty alcohol sulfate in a ratio of 1.5:0.5:3; the penetration waterproof component is methyltriethoxysilane; Step 5, mixing the adhesive material B obtained in step 2, the modified super absorbent resin self-repairing liquid obtained in step 3 and the working property regulator in step 4 to obtain an adhesive material C; Step 6: Mix the cementing material C, coarse silt (≥150 μm) and water in a ratio of 1:4:0.4, fill them into a flood prevention stone mold, naturally cure for 12 hours, and demold to obtain an artificial flood prevention stone.

[0038] Example 3 The raw materials and weight proportions of the solid waste-based Yellow River sediment cementitious material are as follows: 400 parts of Yellow River silt, 100 parts of power plant slag ash, 60 parts of steel plant slag, 35 parts of alum stone tailings, 40 parts of Glauber's salt gypsum, 1.5 parts of crack self-repairing material, and 3 parts of workability regulator.

[0039] The above Yellow River silt is obtained by screening the original mixed Yellow River silt and weighing it according to 45% medium sand, 55% coarse sand and fine sand, among which the weight ratio of coarse sand to fine sand is 1:1.

[0040] The preparation steps are as follows: Step 1, drying the original mixed Yellow River silt through a heat pump drying process, crushing it evenly through a jaw crusher after drying, and screening it into three particle sizes, the amount of medium-grade Yellow River silt is increased to 45% of the amount of raw material Yellow River silt, and the fine-grade Yellow River silt and coarse silt are taken in equal weight ratios; the medium-grade Yellow River silt and alum stone tailings are mixed with air flow to a specific surface area of ​​400㎡ / kg, and then mixed with fine-grade Yellow River silt ≤75μm, and further crushed to 700㎡ / kg; to obtain cementitious material A; Step 2, microwave modification, parameters: 700W, 7 minutes, nitrogen protection; mix the adhesive material A with slag ash and steel slag, perform microwave radiation modification according to the above parameters, and activate to obtain the adhesive material B; set aside; Step 3, preparation of modified super absorbent resin self-repairing liquid: 50 parts of SAP particles, 6 parts of sodium ethylenediaminetetramethylenephosphonate, 4 parts of calcium nitrate, 3 parts of sodium silicate, 0.5 parts of triisopropanolamine, and 100 parts of deionized water are added into a magnetic stirrer and stirred for 15 minutes to obtain; Step 4, prepare a working property regulator, and mix and prepare it according to the weight ratio of water-reducing component: antifreeze component: penetration waterproof component = 5:6:1, wherein the water-reducing component is a combination of coumarone resin water-reducing agent, sucrose calcium series water-reducing agent, and aliphatic hydroxy sulfonate series water-reducing agent, and the ratio is 0.5:0.5:2; the antifreeze component is a combination of sodium nitrite, sodium dichromate alkylbenzene sulfonate, and alkylphenol ethylene oxide condensate, and the ratio is 0.5:0.5:3; the penetration waterproof component is a combination of sodium methyl silicate, sodium ethyl silicate, and methyltriethoxysilane, and the ratio is 1:1:0.5.

[0041] Step 5: Mix the above-prepared adhesive material B, the modified super absorbent resin self-repairing liquid and the workability regulator to obtain an adhesive material C; Step 6: Mix the cementing material C, coarse silt (≥150 μm) and water in a ratio of 1:2:0.4, fill them into a flood prevention stone mold, naturally cure for 12 hours, and demold to obtain an artificial flood prevention stone.

[0042] Comparative Example 1 The raw material composition and preparation method of the solid waste-based Yellow River silt cementitious material are the same as those in Example 1, except that the Yellow River silt is not screened during the preparation, and the original mixed Yellow River silt is directly used and divided into three equal parts for the corresponding preparation steps.

[0043] Comparative Example 2 The raw material composition and preparation method of the solid waste-based Yellow River silt cementitious material are the same as those in Example 1, except that in preparation step 1, a common ball mill is used to crush a mixture of medium-sized Yellow River silt and alum stone tailings to a specific surface area of ​​250 m2 / kg.

[0044] Comparative Example 3 The raw material composition and preparation method of the solid waste-based Yellow River silt cementitious material are the same as those in Example 1, except that, during the preparation, the alunite tailings are added after being mixed with the steel slag in step 2.

[0045] Comparative Example 4 The raw material composition and preparation method of the solid waste-based Yellow River silt cementitious material are the same as those in Example 1, except that the microwave modification treatment step 2 is omitted in the preparation.

[0046] Comparative Example 5 The raw material composition and preparation method of the solid waste-based Yellow River silt cementitious material are the same as those in Example 1, except that the crack self-repairing material in the raw material is replaced by ordinary epoxy resin.

[0047] Comparative Example 6 The raw materials and preparation method of the solid waste-based Yellow River silt cementitious material are the same as those in Example 1, except that, during the preparation, Shanshui P·O42.5 cement is used to replace the cementitious material C prepared in steps 1-5, and then the material is prepared according to the ratio of Shanshui P·O42.5 cement, coarse silt and water of 1:3:0.3.

[0048] Comparative Example 7 The raw material composition and preparation method of the solid waste-based Yellow River sediment cementitious material are the same as those in Example 1, except that, in the preparation, the working property regulator in step 4 is replaced by sodium lignin sulfonate (Shandong Huadi MG).

[0049] The flood prevention stones prepared in the above embodiments and comparative examples were subjected to performance tests, and the results are shown in Table 1 below.

[0050]

[0051] The above compressive strength test method complies with the "Technical Specifications for Flood Control Stone" (SL 260-2014); the freeze-thaw test and carbonation test comply with the "Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete" (GB / T 50082-2024); the crack self-repair rate method refers to the crack width closure rate test in the "Technical Code for Self-repairing Concrete" T / CECS 686-2020.

[0052] The test results in Table 1 show that Examples 1-3 all meet the requirements of the Technical Specifications for Flood Control Stone Materials, and the mechanical properties, freeze-thaw resistance, carbonization resistance, self-repair rate and economy of each example are better than those of the comparative example. Example 3 further adjusts the ratio of different solid wastes, adjusts the component combination of the workability regulator, increases the dosage of the workability regulator and the crack self-repairing material, and increases the mortar-sand ratio, and has the best performance in all aspects.

[0053] Compared with the optimal embodiment 3, comparative example 1 uses unscreened original mixed Yellow River silt, the coarse aggregate is unevenly distributed, the density is poor, the 28d compressive strength is reduced by 22%, and the freeze-thaw resistance and carbonization performance are significantly reduced; comparative example 2 only uses an ordinary ball mill for crushing, the specific surface area is only 250㎡ / kg, the activity of the cementitious material is reduced, and the 12h strength is reduced by 53.9%; comparative example 3 alum stone tailings are added late, the adsorption effect on the silt is weakened, and the silt particles form a large number of interface transition zones around the cementitious material, which affects the density and mechanical properties, the freeze-thaw resistance is reduced by 60%, and the crack self-repair efficiency is reduced; comparative example 4 has no microwave modification, the volcanic ash reaction is delayed, and the 28-day strength is only 69.2% of that of embodiment 3; comparative example 5 has a poor self-repair effect, and the self-repair rate is only 40%, After absorbing water and swelling, the bonding force with the matrix is ​​weak and the durability is reduced; Comparative Example 6 uses ordinary Portland cement, which has poor applicability with Yellow River silt, and its mechanical properties and durability are significantly reduced. Compared with Example 3, the unit cost is increased by 56%; Comparative Example 7 uses a conventional workability regulator, which has poor workability, resulting in poor density of the prepared defense stone, affecting its mechanical properties.

[0054] Figure 1 The microscopic morphology of the stone hydration 28d prepared for Example 1, Example 3 and Comparative Example 6 shows that the CSH gel in Example 1 and Example 3 densely fills the pores, the calcium aluminate crystals are interwoven into a network, and the cracks are completely repaired, while the pores in Comparative Example 6 are obvious, the unreacted particles are accumulated, and the crack width remains>0.2 mm.

[0055] The above specific implementation manner cannot be used as a limitation on the protection scope of the present invention. For those skilled in the art, any substitution, improvement or change made to the implementation manner of the present invention falls within the protection scope of the present invention.

[0056] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A solid waste-based Yellow River sediment cementitious material, characterized in that: The invention comprises the following raw materials in parts by weight: 300-500 parts of Yellow River sediment, 80-130 parts of slag ash, 40-80 parts of steel slag, 20-50 parts of alum stone tailings, 25-55 parts of mirabilite gypsum, 0.5-1.5 parts of crack self-repairing material and 1-3 parts of workability regulator.

2. The solid waste-based Yellow River sediment cementitious material according to claim 1, characterized in that: The Yellow River silt includes coarse silt, fine silt and medium-sized silt; the particle size of coarse silt is ≥150μm, the particle size of fine silt is ≤75μm, and the particle size of medium-sized silt is 75-150μm.

3. The solid waste-based Yellow River sediment cementitious material according to claim 2, characterized in that: The medium-grained sediment accounts for 45% of the total weight of the Yellow River sediment; the coarse sediment and fine sediment are in equal weight ratios.

4. The solid waste-based Yellow River sediment cementitious material according to claim 1, characterized in that: The crack self-repairing material is a modified highly absorbent resin self-repairing liquid, which is prepared as follows: Add 50 parts of SAP particles, 5-7 parts of sodium ethylenediaminetetramethylenephosphonate, 3-5 parts of calcium nitrate, 3-5 parts of sodium silicate, 0.5-1.5 parts of triisopropanolamine and 100-120 parts of deionized water into a magnetic stirrer and stir for 15-20 minutes to obtain the product.

5. The solid waste-based Yellow River sediment cementitious material according to claim 1, characterized in that: The workability regulator comprises a water reducing component, an antifreeze component and a penetration waterproof component, and the weight ratio of the three components is 3-5:6-9:0.5-2.

6. The solid waste-based Yellow River sediment cementitious material according to claim 5, characterized in that: The water-reducing component is one or more of polycyclic aromatic sulfonate water-reducing agent, melamine resin water-reducing agent, coumarone resin water-reducing agent, sucrose calcium water-reducing agent, and aliphatic hydroxy sulfonate water-reducing agent; the antifreeze component is one or more of sodium chloride, sodium nitrite, sodium dichromate alkylbenzene sulfonate, alkylphenol ethylene oxide condensate, and fatty alcohol sodium sulfate; the penetration waterproof component is one or more of triethanolamine, sodium methyl silicate, sodium ethyl silicate, methyltriethoxysilane, and n-propyltrimethoxysilane.

7. The solid waste-based Yellow River sediment cementitious material according to claim 1, characterized in that: The specific surface area of ​​the Yellow River sediment is 50-150㎡ / kg, and the cumulative content of CaO and SiO2 is ≥60%; the specific surface area of ​​steel slag is 310-390㎡ / kg, and the cumulative content of CaO, SiO2 and Al2O3 is 60-75%; the specific surface area of ​​alunite tailings is 220-280㎡ / kg, the CaO content is ≥40%, and the potassium aluminum sulfate content is 0.5-3%; the calcium sulfate content of Glauber's salt gypsum is ≥85%, and the sodium sulfate content is ≥2%.

8. A method for preparing artificial flood prevention stones using the solid waste-based Yellow River sediment cementitious material according to any one of claims 1 to 7, characterized in that: The steps are as follows: Step 1: The original mixed Yellow River sediment is screened into three particle sizes: fine sediment ≤75μm, medium-sized sediment 75-150μm, and coarse sediment ≥150μm for later use; Step 2: Mix the medium-sized sediment and alum stone tailings, crush them to a specific surface area of ​​300-400 m2 / kg, then mix them with fine sediment, and further crush them to 650-750 m2 / kg to obtain cementitious material A; Step 3: Evenly mix the adhesive material A with the slag ash and steel slag; adjust the microwave power to 650-700W, the time to 5-7min, the frequency to 2.4GHz, and nitrogen protection to perform microwave radiation modification to further activate the material to obtain the adhesive material B, which is then mixed with Glauber's salt gypsum, crack self-repairing material and workability regulator to obtain the adhesive material C; Step 4: Mix and stir the cementing material C, coarse mud and water in a weight ratio of 1:2-5:0.25-0.4, fill them into a flood prevention stone mold, and demould after natural curing to obtain an artificial flood prevention stone.

9. The method according to claim 8, characterized in that In step 1, the original mixed Yellow River silt is dried and crushed before screening; the drying is carried out by heat pump drying, and the crushing is carried out by a jaw crusher.

10. The method according to claim 8, characterized in that Step 2: Use ultra-fine air flow mill to crush in steps.

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