Preparation method and application of silt solidified small prefabricated part for slope protection

Abstract

The invention discloses a preparation method of a silt solidified small prefabricated part for slope protection, which comprises the following steps: S1, detecting the moisture content of aeolian sand and fly ash, and determining whether to dry or not according to the moisture content; s2, weighing the aeolian sand and the fly ash according to the proportion, performing uniform dry mixing, then adding water according to the formula amount, and performing stirring until a uniform wet mixture is formed; s3, filling the wet mixture into a steel mold, and carrying out static pressure molding or compaction molding; and S4, removing the mold after the product is formed, and naturally curing the green body to obtain the prefabricated part. By controlling the raw material ratio, the static pressure forming pressure and the compaction time, the compactness and the final strength of the component can be stably controlled, and the strength (the compressive strength within 7 days can reach 3-5 MPa or above through testing) of the component can completely meet the requirements of low-stress or non-bearing projects such as side slope protection, sand stabilization and sand blocking and simple roadbed slope protection in desert and gobi areas; and the small prefabricated parts are convenient to manually carry and quickly build, and the construction is flexible.

Description

Technical Field

[0001] This invention belongs to the field of building materials and solid waste resource utilization technology, specifically relating to a method for preparing and applying small precast silt-cured components for slope protection. Background Technology

[0002] In coal-rich regions of my country, such as Xinjiang and Inner Mongolia, coal-fired power generation produces large quantities of fly ash. Fly ash is the fine ash carried by flue gas after the high-temperature combustion of pulverized coal, collected over time. Its main chemical composition is similar to clay, classifying it as a major industrial solid waste. Traditionally, fly ash disposal has primarily involved stockpiling, which occupies land and poses environmental risks. Meanwhile, many of these major coal-fired power plant production areas are located around the Gobi Desert, rich in aeolian sand resources, but lacking traditional building materials (such as cement and aggregates), requiring long-distance transportation, resulting in high infrastructure construction costs and significant environmental pressure.

[0003] Existing technologies have been studied for preparing building materials using fly ash and sand, but these technologies typically suffer from the following problems: 1) A large amount of cement or other cementitious materials need to be added to ensure strength, resulting in high costs; 2) The preparation process is complex, often requiring sintering or steam curing, resulting in high energy consumption; 3) The resulting products are large in size or weight, making them unsuitable for small-scale, decentralized engineering applications in areas with poor transportation, such as deserts and Gobi, especially in scenarios such as slope protection and sand fixation where the absolute strength of the materials is not a high priority but convenience and economy are of paramount importance.

[0004] Therefore, there is an urgent need to develop a green building material that can be sourced locally, has a simple manufacturing process, is inexpensive, and is suitable for small-scale protective projects in desert areas. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the main objective of this invention is to provide a method for preparing small precast silt-stabilized components for slope protection; this method is simple, requires no sintering, produces products with strength meeting the requirements of low-stress engineering projects such as slope protection, and achieves the dual goals of solid waste resource utilization and reduced building material costs.

[0006] The present invention also discloses the application of the aforementioned silt-cured small prefabricated components in slope protection, sand fixation, or sand prevention projects in desert or Gobi areas.

[0007] The objective of this invention is achieved through the following technical solution: A method for preparing small precast silt-cured components for slope protection includes the following steps: S1. Raw material pretreatment: The moisture content of aeolian sand and fly ash is tested, and a decision is made on whether to carry out drying treatment based on the moisture content; S2. Ingredients and mixing: Weigh the aeolian sand and fly ash according to the formula, dry mix them evenly, then add the water according to the formula and stir until a uniform wet mixture is formed. S3. Static pressing or vibration molding: The wet mixture is filled into a steel mold and subjected to static pressing or vibration molding; S4. Demolding and Curing: After the product is formed, the mold is removed and the blank is naturally cured to obtain the precast component.

[0008] In step S1, the natural moisture content of aeolian sand and fly ash is measured. If the moisture content is high, it is dried and air-dried to 0.8-2%. If the natural moisture content of aeolian sand and fly ash can be kept stable, or the testing of each batch of raw materials can be strengthened, the natural moisture content can be reasonably utilized to reduce the amount of water added during mixing.

[0009] In some specific embodiments, the prefabricated component comprises the following components by mass percentage: 55%~65% aeolian sand, 35%~45% fly ash; and the amount of water added is 6%~8% of the total mass of the aeolian sand and fly ash.

[0010] Furthermore, the mass ratio of the aeolian sand to fly ash is (40-80):(30-50).

[0011] In some specific embodiments, in step S3, the steel mold is in the shape of a cuboid, a hexagon, or an irregular block.

[0012] In some specific embodiments, the static pressure forming pressure in step S3 is 200-300KN, and the holding time is 30-60 seconds.

[0013] In some specific embodiments, the vibration compaction in step S3 uses vibration equipment that conforms to the JC / T 682-2022 standard "Vibration Compaction Table for Cement Mortar Specimens".

[0014] In some specific embodiments, the relative humidity of the environment for natural curing in step S4 is not less than 40%, and the curing time is not less than 7 days.

[0015] As part of the same inventive concept, this invention also provides an application of the small precast silt-stabilized components for slope protection prepared by the aforementioned method in slope protection, sand fixation, or sand prevention projects in desert or Gobi areas.

[0016] Compared with the prior art, the present invention has at least the following advantages: 1) Significant benefits in resource utilization and environmental protection: Using bulk industrial solid waste fly ash and abundant desert aeolian sand as the main raw materials, it has achieved "desertification control with waste", which has greatly reduced the environmental burden of fly ash storage and saved traditional building material resources. 2) Low cost and local sourcing: The raw materials are sourced locally, with almost no transportation costs. The production process is simple, requiring no high-temperature sintering or complex curing. Equipment investment and energy consumption are extremely low, making it particularly suitable for promotion and application in remote desert areas. 3) Strong product applicability: Although the strength of the final product is lower than that of conventional concrete, its strength (tested to be 3-5 MPa or more after 7 days) can fully meet the requirements of low-stress or non-load-bearing projects such as slope protection, sand fixation and sand retention, and simple roadbed slope protection in desert and Gobi areas; and the miniaturized prefabricated components are easy to handle manually and quickly build, making construction flexible. 4) Controllable technology and stable quality: By controlling the raw material ratio (especially the critical water-cement ratio) and static pressing pressure and vibration time, the density and final strength of the components can be stably controlled, and the production process is simple and reliable. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0018] When a quantity, concentration, or other value or parameter is described as a range, preferred range, or preferred upper and lower limits, it should be understood that it is equivalent to specifically disclosing any range by combining any pair of upper or preferred values ​​with any lower or preferred values, regardless of whether the range is specifically disclosed. Unless otherwise stated, the numerical range values ​​listed herein include the endpoints of the range and all integers and fractions within that range.

[0019] Unless otherwise stated, all percentages, parts, ratios, etc. in this document are by weight.

[0020] The materials, methods, and embodiments described herein are exemplary and should not be construed as limiting unless otherwise stated.

[0021] In the following embodiments, the aeolian sand is native fine sand from desert areas, with a particle size mainly concentrated between 0.075mm and 0.25mm.

[0022] Example 1 This embodiment provides a method for preparing small precast silt-stabilized components for slope protection, including the following steps: 1) The reconstruction and expansion project of the S240 Zhundong Dajing Service Area to Qitai Highway will take aeolian sand from the Kurbantunggut Desert in Xinjiang, which will be dried and passed through a 2mm sieve; and take Class F II fly ash from Jiangbu Power Plant. 2) Weigh the raw materials according to the dry weight ratio of aeolian sand: fly ash = 60:40. After mixing the dry materials (aeolian sand and fly ash) evenly, add 7% of clean water according to the total weight of the dry materials and stir until uniform to obtain wet mixture. 3) Fill the mixture into a steel mold with an inner cavity size of 800mm×100mm×100mm, and statically press it under a pressure of 300KN for 45 seconds; after demolding, place the blank in a shed with a relative humidity of about 40% for natural curing for 7 days.

[0023] This application tests the precast component prepared in this embodiment. The average compressive strength of the precast component after curing is 4.2 MPa, which can be used for grid-like slope protection masonry on desert highway slopes.

[0024] Example 2 This embodiment provides a method for preparing small precast silt-stabilized components for slope protection, including the following steps: 1) The reconstruction and expansion project of the S240 Zhundong Dajing Service Area to Qitai Highway will take aeolian sand from the Kurbantunggut Desert in Xinjiang, with a natural moisture content of 1.6% and will not be dried, and will take Class F II fly ash from the Lanshan Tunhe Power Plant; 2) Weigh the raw materials according to the mass ratio of aeolian sand to fly ash = 58:42, add water accounting for 6.5% of the total mass of sand, stir evenly to obtain wet mixture; 3) Fill the wet-mixed material into a special steel mold for manufacturing hexagonal prisms, and use a cement mortar specimen molding and vibration table to form the prism. Vibrate for 60 seconds, and then let it cure naturally for 10 days after demolding.

[0025] This application tests the precast component prepared in this embodiment. The cured precast component is lightweight and has a compressive strength of about 3.8 MPa, and can be used to create sand-fixing grid sand barriers.

[0026] Comparative Example 1 This comparative example provides a method for preparing small precast silt-stabilized sand components for slope protection. Its components and proportions are basically the same as in Example 2, except that only aeolian sand is used, and 10% water by mass of the aeolian sand is added. Specifically: 1) The reconstruction and expansion project of the S240 Zhundong Dajing Service Area to Qitai Highway takes aeolian sand from the Kurbantunggut Desert in Xinjiang, with a natural moisture content of 1.6% and is not dried; 2) Take 50 kg of aeolian sand, add water accounting for 10% of the total mass of the aeolian sand, stir evenly to obtain wet mixture; The process steps and parameters of steps 3) and 4) are the same as those in Example 2.

[0027] The precast components in this comparative example are loose after demolding, unable to maintain their shape, and lack strength after curing.

[0028] Comparative Example 2 This comparative example provides a method for preparing small precast silt-stabilized components for slope protection. Its components and proportions are basically the same as in Example 1, except that only fly ash is used, and 20% water is added. Specifically: 1) Use Class F, Grade II fly ash from Jiangbu Power Plant; 2) Take 50 kg of fly ash, add 7% of clean water (based on the total mass of fly ash), and stir until uniform to obtain a wet mixture. The process steps and parameters of steps 3) and 4) are the same as those in Example 1.

[0029] The precast components in this comparative example, after being pressed into shape under 300KN pressure, require a long curing period and are prone to cracking during drying. Their strength development is slow, and their cost is significantly higher than that of the technical solution in this application.

[0030] In summary, this invention, through a specific ratio of aeolian sand and fly ash, and by controlling the appropriate amount of water added and the static pressure and vibration compaction process, can obtain a solidified body with practical engineering strength without the need for expensive cementitious materials such as cement. Its performance stems from the weak reaction between the pozzolanic activity of fly ash and the surface of sand particles under the influence of moisture, as well as the mechanical interlocking and physical adsorption effects formed by high-pressure compaction. This product is an innovative green building material suitable for specific geographical and engineering conditions.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for preparing small precast silt-cured components for slope protection, characterized in that, Includes the following steps: S1. Raw material pretreatment: The moisture content of aeolian sand and fly ash is tested, and a decision is made on whether to carry out drying treatment based on the moisture content; S2. Ingredients and mixing: Weigh the aeolian sand and fly ash according to the ratio, dry mix them evenly, add the water according to the formula, and stir until a uniform wet mixture is formed. S3. Static pressing or vibration molding: The wet mixture is filled into a steel mold and subjected to static pressing or vibration molding; S4. Demolding and curing: After the product is formed, the mold is removed and the blank is naturally cured to obtain the precast component.

2. The method for preparing small precast silt-cured components for slope protection according to claim 1, characterized in that, The precast components comprise the following components by mass percentage: 55%~65% aeolian sand, 35%~45% fly ash; and water is added at 6%~8% of the total mass of the aeolian sand and fly ash.

3. The method for preparing small precast silt-cured components for slope protection according to claim 2, characterized in that, The mass ratio of the aeolian sand to fly ash is (40-80):(30-50).

4. The method for preparing small precast silt-cured components for slope protection according to claim 1, characterized in that, In step S3, the steel mold is in the shape of a cuboid, a hexagon, or an irregular block.

5. The method for preparing small precast silt-cured components for slope protection according to claim 4, characterized in that, The static pressure forming pressure in step S3 is 200-300KN, and the holding time is 30-60 seconds.

6. The method for preparing small precast silt-cured components for slope protection according to claim 4, characterized in that, The vibration compaction process in step S3 uses vibration equipment that conforms to the JC / T 682-2022 standard "Vibration Compaction Table for Cement Mortar Specimens".

7. The method for preparing small precast silt-cured components for slope protection according to claim 1, characterized in that, The relative humidity of the environment for natural curing described in step S4 shall not be lower than 40%, and the curing time shall not be less than 7 days.

8. The application of a small precast silt-stabilized component for slope protection prepared by any one of claims 1-7 in slope protection, sand fixation or sand prevention projects in desert or Gobi areas.