A full-solid-waste marine concrete prefabricated part free of steam curing and a preparation method thereof

Abstract

The application belongs to the technical field of building materials, and particularly relates to a full-solid-waste marine concrete prefabricated part free of steam curing and a preparation method thereof. The base material of the full-solid-waste marine concrete prefabricated part free of steam curing comprises full-solid-waste cementitious material, large stone, small stone, fine aggregate, water reducing agent and water. The full-solid-waste cementitious material comprises steel slag, blast furnace slag, refining slag and desulfurization gypsum. In the preparation process, the prefabricated part does not need steam curing and only needs standard curing for 28 days to obtain a C60 grade. The prefabricated part uses full-solid-waste cementitious material to replace traditional cement, reduces carbon emission in the cement production process, and provides an effective resource recycling way for solid waste in the metallurgical industry. Through the synergistic effect of various solid waste materials, the durability is significantly improved. Through the reasonable use of industrial solid waste, the resource consumption and waste emission are reduced, which is helpful to realize sustainable development and provides a new idea for the resource utilization of solid waste.

Description

Technical Field

[0001] This application belongs to the field of building materials technology, specifically relating to a precast marine concrete component that does not require autoclaving and is made from solid waste, and its preparation method. Background Technology

[0002] The steel industry generates massive amounts of metallurgical slag during production, primarily blast furnace slag and steel slag. Statistics show that approximately 0.3 tons of granulated blast furnace slag and 0.13 tons of steel slag are produced for every ton of crude steel produced. However, the comprehensive utilization rate of metallurgical slag is low. Its large-scale stockpiling not only occupies valuable land resources but also poses potential environmental pollution risks, severely hindering the sustainable development of enterprises.

[0003] Traditional concrete preparation relies on cement clinker as the main component, but the cement production process generates high carbon emissions and natural sand and gravel resources are constantly decreasing. With the advancement of the national "dual carbon" strategy and the deepening of the circular economy policy, the construction industry has an increasingly urgent need for resource-saving and environmentally friendly materials. Utilizing industrial solid waste to prepare concrete has become an important development direction for green building materials.

[0004] All-solid-waste concrete refers to concrete whose cementitious materials and aggregates are entirely derived from solid waste, without the use of any cement or cement clinker. In recent years, based on new theories such as "multi-solid-waste synergy," "complex salt effect," and "silicon tetracoordination isomorphism effect," concrete with strength grades of C60 or even higher has been successfully prepared using solid wastes such as steel slag, blast furnace slag, and desulfurized gypsum, laying the foundation for the application of all-solid-waste technology in structural engineering. However, existing technologies mostly focus on general engineering fields, and research on the application of marine concrete in harsh marine environments remains insufficient.

[0005] Existing solid waste-based concrete generally suffers from problems such as low early strength, uncontrollable setting time, and poor volume stability. In marine engineering, it is also necessary to consider resistance to chloride ion penetration, carbonation, and freeze-thaw cycles. In addition, most high-performance solid waste concrete requires steam curing to improve early strength, which limits the promotion and application of solid waste concrete in the field of precast components. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a precast marine concrete component made entirely of solid waste and without steam curing, and its preparation method. The aim is to develop a high-strength precast marine concrete component made entirely of solid waste and without steam curing, possessing both technological innovation value and promising engineering application prospects. This precast marine concrete component uses various industrial solid wastes as the sole cementitious material and aggregate, without adding any cement clinker, resulting in low production costs. It also exhibits resistance to chloride ion penetration, carbonation, and volume stability. Furthermore, its preparation process requires no steam curing, achieving a compressive strength of ≥60 MPa after 28 days at room temperature.

[0007] According to the first aspect of this application, this application provides a precast marine concrete component made entirely of solid waste without autoclaving, the matrix material of which includes: solid waste cementitious material, large stones, small stones, fine aggregate, water-reducing agent and water; The mass ratio of the solid waste cementitious material, the large stones, the small stones, and the fine aggregate is (217~234):(321~331):(79~83):(355~368), the water-cement ratio is (0.20~0.26):1, and the mass ratio of water to the water-reducing agent is (24.5~29):1. The all-solid waste cementitious material uses steel slag, blast furnace slag, refining slag, and desulfurization gypsum as raw materials, and the specific surface area of ​​the all-solid waste cementitious material is greater than 550 m². 2 / kg; The aging time of the steel slag is greater than or equal to 2 months, and the aging time of the blast furnace slag is greater than or equal to 14 days and less than 12 months.

[0008] Furthermore, the mass ratio of the steel slag, the blast furnace slag, the refining slag, and the desulfurized gypsum in the solid waste cementitious material is (20~25):(55~60):(3~5):(13~17).

[0009] Furthermore, the steel slag includes at least one of dicalcium silicate (Ca2SiO4), calcium ferrite (Ca2Fe2O5), or RO phase; the blast furnace slag includes a glassy state; the desulfurized gypsum includes calcium sulfate dihydrate (CaSO4·2H2O); and the refining slag includes at least one of calcium aluminate mineral (CaO·Al2O3), calcium silicate mineral (CaO·SiO2), or calcium iron ore (CaFe2O4).

[0010] Furthermore, the large stones have a particle size greater than 10 mm and less than or equal to 20 mm, and the small stones have a particle size greater than 5 mm and less than or equal to 10 mm.

[0011] Furthermore, the large stones and the small stones include waste stones.

[0012] Furthermore, the fine aggregate is composed of coarse sand, and the particle size of the fine aggregate is greater than or equal to 0.16 mm and less than or equal to 5 mm.

[0013] Furthermore, the water-reducing agent includes a polycarboxylate water-reducing agent.

[0014] Furthermore, the preparation method of the all-solid waste cementitious material is as follows: a. Weigh the raw materials and dry them in the dark; b. Grind the dried raw material; c. The ground raw material is sieved to obtain the all-solid waste cementitious material, wherein the specific surface area of ​​the all-solid waste cementitious material is greater than 550 m². 2 / kg.

[0015] Furthermore, the temperature for drying the steel slag, blast furnace slag, and refining slag in the dark is 50~200℃, and the temperature for drying the desulfurized gypsum in the dark is 40~50℃; the grinding time is 80~120min.

[0016] Furthermore, the moisture content of the raw material after being dried in the dark is ≤0.1%.

[0017] Furthermore, the ground raw material is passed through a 2mm standard sieve.

[0018] According to a second aspect of this application, this application provides a method for preparing the above-mentioned autoclaved, solid waste marine concrete precast component, comprising the following steps: S1. Weigh out the solid waste cementitious material, large stones, small stones, fine aggregates, and corresponding water and water-reducing agent. Mix the water and water-reducing agent evenly and divide them into a first mixture and a second mixture with the same mass. Divide the solid waste cementitious material into a first cementitious material and a second cementitious material with the same mass. S2. Mix the large stones, small stones, and fine aggregates with the first mixture for 10 seconds, then add the first cementitious material and stir for 30 seconds, then add the second mixture and the second cementitious material and stir for 3-5 minutes to obtain precast concrete. S3. Pour the precast concrete into the mold, vibrate and scrape it for no more than 30 seconds, and cure it according to standard for 24 hours. Then demold the concrete to obtain the test block. S4. The test block is subjected to standard curing for a predetermined time to obtain a precast component.

[0019] Furthermore, when the predetermined time is 28 days, the compressive strength of the precast component is ≥60MPa.

[0020] This application proposes a precast marine concrete component made entirely from solid waste and without autoclaving, and its preparation method, which produces the following beneficial effects: Replacing traditional cement with all-solid-waste cementitious materials reduces carbon emissions during cement production and provides an effective resource recovery pathway for steel slag, refining slag, blast furnace slag, and desulfurization gypsum in the metallurgical industry; through the synergistic effect of multiple solid waste materials, its durability is significantly improved compared to traditional cement-based concrete; and by rationally utilizing industrial solid waste, resource consumption and waste emissions are reduced, contributing to sustainable development and providing new ideas for the resource utilization of solid waste in other industries. Detailed Implementation

[0021] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] This application provides a precast marine concrete component made entirely of solid waste and requiring no autoclaving, the matrix material of which includes: solid waste cementitious material, large stones, small stones, fine aggregate, water-reducing agent and water; The mass ratio of solid waste cementitious material, large stones, small stones, and fine aggregate is (217~234):(321~331):(79~83):(355~368), the water-cement ratio is (0.20~0.26):1, and the mass ratio of water to water-reducing agent is (24.5~29):1. The all-solid-waste cementitious material uses steel slag, blast furnace slag, refining slag, and desulfurization gypsum as raw materials, and has a specific surface area greater than 550 m². 2 / kg; The aging time for steel slag is greater than or equal to 2 months, and the aging time for blast furnace slag is greater than or equal to 14 days and less than 12 months.

[0023] The mechanism of action of the all-solid-waste concrete system is a synergistic process of multiple solid wastes. In the all-solid-waste cementitious material of this application, steel slag, blast furnace slag, refining slag, and desulfurization gypsum jointly construct a dense hydration product network mainly composed of CSH gel and ettringite through the tetracoordination effect of silicon, which greatly enhances the later strength of solid waste-based concrete. At the same time, under the action of the double salt effect, many active ions can significantly reduce their solubility in water through the formation of double salt, thereby improving the concrete's resistance to chloride ion penetration, carbonation resistance, and volume stability.

[0024] By rationally controlling the aging time of steel slag and blast furnace slag, the performance of all-solid waste cementitious materials can be effectively improved, ensuring their effectiveness in concrete, especially in terms of strength, impermeability, and durability. The core of rationally controlling the aging time of steel slag and blast furnace slag lies in simultaneously achieving the synergistic optimization of "steel slag volume stabilization," "blast furnace slag activity retention," and "improved grindability." On the one hand, if the free CaO, free MgO, and some unstable phases in steel slag are not aged sufficiently, they will continue to slowly hydrate under the action of water after entering the concrete, resulting in volume expansion, inducing microcracks, increasing pore connectivity, and thus weakening strength, impermeability, and durability. On the other hand, moderate aging allows these expansion sources to gradually hydrate / carbonate and stabilize before entering the mill, significantly reducing the risk of "delayed expansion" in the later stages. On the other hand, the activity of blast furnace slag mainly comes from the potential hydraulic properties of the glassy phase. If it is over-aged under humid conditions, slight pre-hydration or carbonation can easily occur on the particle surface, forming a film of low-reactivity hydration products. This leads to a decrease in the early dissolution-reaction rate of the hydration reaction, resulting in a sharp drop in early strength and affecting processes such as concrete demolding. Therefore, controlling the aging time and storage environment can better maintain the activity of blast furnace slag, allowing it to release its hydration reaction potential in the system as needed. In addition, volume changes during the aging process induce the formation of microcracks and defect networks inside the particles. These microcracks can reduce the integrity of the particle structure and fracture energy, improve the grindability of the raw materials, and make it easier to obtain a higher specific surface area and a more reasonable particle size distribution during grinding, thereby further improving the early nucleation / hydration efficiency. Under the combined effect, the system has fewer microcrack sources, enhanced gel formation and filling, and a denser pore structure, ultimately resulting in more complete concrete strength development, lower permeability channel connectivity, and better long-term durability.

[0025] The preferred method for preparing the all-solid waste cementitious material is as follows: a. Weigh the raw materials according to the following mass ratio: steel slag: blast furnace slag: refining slag: desulfurized gypsum = (20~25):(55~60):(3~5):(13~17), and dry the steel slag, blast furnace slag and refining slag in the dark at 50~200℃, and dry the desulfurized gypsum in the dark at 40~50℃. b. In the SM-500 cement test mill, cylindrical steel segments are used as grinding media to grind the dried raw materials. The mass ratio of cylindrical steel segments to raw materials is (22~24):1. The diameter of the cylindrical steel segments is 20mm and the length is 20~40mm. c. Pass the ground raw material through a 2mm standard sieve to obtain a specific surface area greater than 530m². 2 / kg of all solid waste cementitious materials.

[0026] In the above-mentioned method for preparing solid waste cementitious materials, controlling the temperature for drying desulfurized gypsum in the dark to 40-50°C can prevent the gypsum from decomposing into hemihydrate gypsum at excessively high temperatures. In some preferred embodiments of this application, in an SM-500 type cement test mill, cylindrical steel segments are used as grinding media to grind the dried raw materials. The mass ratio of the cylindrical steel segments to the raw materials is (22-24):1, and the diameter of the cylindrical steel segments is 20 mm and the length is 20-40 mm. SM-500 type The single-load capacity of the cement test mill is 5 kg, and its standard steel ball media loading capacity is 100 kg. In this application, the full-section grinding media (cylindrical steel segments) used in the SM-500 cement test mill is generally more conducive to improving the grinding efficiency and product uniformity in the fine grinding stage compared with the standard steel ball media: the steel segments are more likely to form line contact and provide stronger shearing and grinding effects, so that the particles are refined faster and the particle size distribution is more concentrated under the mechanism dominated by "grinding + shearing". At the same time, it can reduce the over-grinding and gradation imbalance caused by simple impact to a certain extent. Furthermore, there is a key advantage to steel slag-containing systems: steel slag often contains metallic iron particles. These iron particles are inherently tough and extremely difficult to grind. If steel balls are used for strong impact, the iron particles are often repeatedly "flattened / crushed" into finer metal fragments. This not only consumes a large amount of ineffective grinding energy and exacerbates wear, but also causes these inert metal particles to mix into the powder, affecting fineness characterization and particle size distribution, thus adversely affecting the performance stability of the cementitious material. In contrast, the abrasive action of steel segments tends to "peel off and disintegrate" the brittle coating layer (mineral attachment layer) on the surface of the iron particles, allowing the iron particles to be released in a more complete form without being excessively crushed. This reduces the interference of difficult-to-grind metals in the grinding process, resulting in more fully refined effective active components and a more homogeneous system in the final solid waste-based cementitious material. Macroscopically, this is more conducive to the stable improvement of strength development and durability performance.

[0027] Furthermore, the mass ratio of cylindrical steel segments to raw materials is (22~24):1. When the raw material loading is 5kg, the cylindrical steel segments weigh 10~20kg more than the grinding media in a standard laboratory mill. This not only effectively improves the particle size distribution of the powder and enhances the reactivity of the solid waste cementitious materials, but also optimizes the workability, mechanical properties, and durability of concrete. Specifically, a more uniform particle size distribution allows the cementitious materials to participate more fully in the reaction during hydration, promoting the formation of hydration products and thus improving the early and later strength of concrete. Simultaneously, this improvement also enhances the fluidity and workability of concrete, making it easier to shape and vibrate during construction, ensuring the quality and consistency of precast components. In terms of durability, a uniform particle size distribution helps improve the density of concrete, reduces the penetration rate of moisture and harmful ions, thereby enhancing the concrete's resistance to permeability, carbonation, and freeze-thaw cycles in harsh environments.

[0028] On the other hand, this application provides a method for preparing precast marine concrete components that do not require autoclaving and are made entirely from solid waste, comprising the following steps: S1. Weigh out the solid waste cementitious material, large stones, small stones and fine aggregates in a mass ratio of (217~234):(321~331):(79~83):(355~368). Weigh out the corresponding water and water-reducing agent in a water-cement ratio of (0.20~0.26):1 and a mass ratio of (24.5~29):1. Mix the water and water-reducing agent evenly and divide them into a first mixture and a second mixture with the same mass. Divide the solid waste cementitious material into a first cementitious material and a second cementitious material with the same mass. S2. Mix the large stones, small stones, and fine aggregates with the first mixture for 10 seconds, then add the first cementitious material and mix for 30 seconds, then add the second mixture and the second cementitious material and mix for 3-5 minutes to obtain precast concrete. S3. Pour the precast concrete into the mold, vibrate and scrape it for no more than 30 seconds, and cure it according to standard for 24 hours. Then demold the concrete to obtain the test block. S4. Perform standard curing on the test block to obtain marine precast components.

[0029] In the above-mentioned method for preparing precast marine concrete components from non-steam-cured solid waste, calcium-silicon-aluminum solid waste such as steel slag and blast furnace slag are treated with SO4 provided by desulfurization gypsum. 2- OH dissolved from steel slag - Under co-excitation, the [SiO4] in the glassy matrix first depolymerizes. 2- [AlO4] 5- Tetrahedrons form oligomeric silicon (aluminum) oxide anions; subsequently, through the "double salt effect," they react with Ca... 2+ The process combines acicular ettringite and C-(A)-SH gel, which are generated simultaneously. The ettringite rapidly builds the early framework, while the C-(A)-SH continuously fills the pores. Together, they rapidly densify the slurry, achieving a compressive strength of over 60 MPa in precast sections after 28 days under steam-free curing conditions. Furthermore, the Cl-... - CO3 2-Harmful ions are chemically solidified within the gel and double salt lattice, significantly improving marine engineering durability. The core of this technology lies in the influence of the "double salt effect" and the "silicon tetracoordination isomorphism effect" on hydration products. During hydration, solid waste materials such as steel slag, blast furnace slag, and desulfurized gypsum form low-solubility salts through double salt reactions. These salts effectively reduce the solubility of harmful substances like chloride ions, thereby improving the concrete's resistance to chloride ion penetration. Especially in marine environments, chloride ion penetration severely affects the long-term performance of concrete; the introduction of the double salt effect enhances concrete durability. The silicon tetracoordination isomorphism effect allows the active silicon components in steel slag and blast furnace slag to rapidly participate in the hydration reaction, generating hydration products with high strength and stability (such as CSH gel). This gel network structure enhances the compactness of concrete and reduces water penetration, thereby improving carbonation resistance and freeze-thaw resistance. The refined slag is rich in aluminate mineral phases (such as tricalcium aluminate and dodecacalcium heptaaluminate), which have extremely high reactivity. During hydration, they can react rapidly and release heat, thereby increasing the system's reaction temperature and reducing setting time. This allows the concrete to reach higher strength more quickly under non-steam curing conditions. Through the design of this composite material system, this application not only achieves a breakthrough in strength but also significantly improves the durability of concrete, making it particularly suitable for harsh environments such as marine engineering.

[0030] The technical solution of this application will be further described below with reference to specific embodiments. It should be noted that the solid waste cementitious material used in the following embodiments is composed of the following raw materials in parts by weight: 15 parts of primary steel slag, 10 parts of secondary steel slag, 55 parts of blast furnace slag, 5 parts of refining slag, and 15 parts of desulfurization gypsum. The aging time of primary steel slag is 2 months, and the aging time of blast furnace slag is 1 month. The particle size of large stones is greater than 10 mm and less than or equal to 20 mm, the particle size of small stones is greater than 5 mm and less than or equal to 10 mm, and the fine aggregate is composed of coarse sand with a particle size greater than or equal to 0.16 mm and less than or equal to 5 mm.

[0031] The preparation method of all-solid waste cementitious materials is as follows: a. Weigh the above-mentioned parts by weight of raw materials and dry them in a constant temperature oven at 50°C in the dark. b. In the SM-500 cement test mill, cylindrical steel segments are used as grinding media to grind the dried raw materials. The mass ratio of the cylindrical steel segments to the raw materials is 24:1. c. Pass the ground raw material through a 2mm standard sieve to obtain a specific surface area greater than 550m². 2 / kg of all solid waste cementitious materials.

[0032] Example 1 This embodiment provides a precast marine concrete component made entirely of solid waste and requiring no autoclaving. The matrix material includes the following components by weight: 225 parts of solid waste cementitious material, 329 parts of large stones, 82 parts of small stones, 364 parts of fine aggregate, 2 parts of water-reducing agent, and 49 parts of water.

[0033] The above-mentioned materials are used to prepare precast marine concrete components that do not require autoclaving and are made from solid waste. The preparation method includes the following steps: S1. Weigh the components in the above weight proportions, mix the water and water-reducing agent evenly and divide them into a first mixture and a second mixture with the same mass, and divide the solid waste cementitious material into a first cementitious material and a second cementitious material with the same mass. S2. Mix the large stones, small stones, fine aggregates and the first mixture for 10 seconds, then add the first cementitious material and mix for 30 seconds, then add the second mixture and the second cementitious material and mix for 2 minutes to obtain precast concrete. S3. Pour the precast concrete into a 100mm×100mm×100mm mold, and use a universal press to place it on a concrete vibration table and vibrate and scrape it for 30 seconds according to the requirements for the unconfined compressive strength test of high-performance concrete materials made from all solid waste in the "Technical Specification for Application of High-Performance Concrete Made from All Solid Waste" T / CECS 1254-2023. Then, cure it at 40℃ for 24 hours and demold it to obtain the test block. S4. Place the test block in a standard curing chamber with a temperature of 20±2℃ and a relative humidity of 95% for standard curing to obtain the precast component.

[0034] Example 2 This embodiment provides a precast marine concrete component made entirely of solid waste and requiring no autoclaving. The matrix material comprises the following components by weight: 226 parts of solid waste cementitious material, 328 parts of large stones, 82 parts of small stones, 364 parts of fine aggregate, 2 parts of water-reducing agent, and 54 parts of water.

[0035] The above-mentioned materials are used to prepare precast marine concrete components that do not require autoclaving and are made from solid waste. The preparation method includes the following steps: S1. Weigh the components in the above weight proportions, mix the water and water-reducing agent evenly and divide them into a first mixture and a second mixture with the same mass, and divide the solid waste cementitious material into a first cementitious material and a second cementitious material with the same mass. S2. Mix the large stones, small stones, fine aggregates and the first mixture for 10 seconds, then add the first cementitious material and mix for 30 seconds, then add the second mixture and the second cementitious material and mix for 2 minutes to obtain precast concrete. S3. Pour the precast concrete into a 100mm×100mm×100mm mold, and use a universal press to place it on a concrete vibration table and vibrate and scrape it for 30 seconds according to the requirements for the unconfined compressive strength test of high-performance concrete materials made from all solid waste in the "Technical Specification for Application of High-Performance Concrete Made from All Solid Waste" T / CECS 1254-2023. Then, cure it at 40℃ for 24 hours and demold it to obtain the test block. S4. Place the test block in a standard curing chamber with a temperature of 20±2℃ and a relative humidity of 95% for standard curing to obtain the precast component.

[0036] Example 3 This embodiment provides a precast marine concrete component made entirely of solid waste and requiring no autoclaving. The matrix material comprises the following components by weight: 224 parts of solid waste cementitious material, 329 parts of large stones, 82 parts of small stones, 365 parts of fine aggregate, 2 parts of water-reducing agent, and 49 parts of water.

[0037] The above-mentioned materials are used to prepare precast marine concrete components that do not require autoclaving and are made from solid waste. The preparation method includes the following steps: S1. Weigh the components in the above weight proportions, mix the water and water-reducing agent evenly and divide them into a first mixture and a second mixture with the same mass, and divide the solid waste cementitious material into a first cementitious material and a second cementitious material with the same mass. S2. Mix the large stones, small stones, fine aggregates and the first mixture for 10 seconds, then add the first cementitious material and mix for 30 seconds, then add the second mixture and the second cementitious material and mix for 2 minutes to obtain precast concrete. S3. Pour the precast concrete into a 100mm×100mm×100mm mold, and use a universal press to place it on a concrete vibration table and vibrate and scrape it for 30 seconds according to the requirements for the unconfined compressive strength test of high-performance concrete materials made from all solid waste in the "Technical Specification for Application of High-Performance Concrete Made from All Solid Waste" T / CECS 1254-2023. Then, cure it at 40℃ for 24 hours and demold it to obtain the test block. S4. Place the test block in a standard curing chamber with a temperature of 20±2℃ and a relative humidity of 95% for standard curing to obtain the precast component.

[0038] Example 4 This embodiment provides a precast marine concrete component made entirely of solid waste and requiring no autoclaving. The matrix material includes the following components by weight: 217 parts of solid waste cementitious material, 331 parts of large stones, 83 parts of small stones, 368 parts of fine aggregate, 2 parts of water-reducing agent, and 52 parts of water.

[0039] The above-mentioned materials are used to prepare precast marine concrete components that do not require autoclaving and are made from solid waste. The preparation method includes the following steps: S1. Weigh the components in the above weight proportions, mix the water and water-reducing agent evenly and divide them into a first mixture and a second mixture with the same mass, and divide the solid waste cementitious material into a first cementitious material and a second cementitious material with the same mass. S2. Mix the large stones, small stones, fine aggregates and the first mixture for 10 seconds, then add the first cementitious material and mix for 30 seconds, then add the second mixture and the second cementitious material and mix for 2 minutes to obtain precast concrete. S3. Pour the precast concrete into a 100mm×100mm×100mm mold, and use a universal press to place it on a concrete vibration table and vibrate and scrape it for 30 seconds according to the requirements for the unconfined compressive strength test of high-performance concrete materials made from all solid waste in the "Technical Specification for Application of High-Performance Concrete Made from All Solid Waste" T / CECS 1254-2023. Then, cure it at 40℃ for 24 hours and demold it to obtain the test block. S4. Place the test block in a standard curing chamber with a temperature of 20±2℃ and a relative humidity of 95% for standard curing to obtain the precast component.

[0040] Example 5 This embodiment provides a precast marine concrete component made entirely of solid waste and requiring no autoclaving. The matrix material includes the following components by weight: 234 parts of solid waste cementitious material, 321 parts of large stones, 79 parts of small stones, 355 parts of fine aggregate, 2 parts of water-reducing agent, and 58 parts of water.

[0041] The above-mentioned materials are used to prepare precast marine concrete components that do not require autoclaving and are made from solid waste. The preparation method includes the following steps: S1. Weigh the components in the above weight proportions, mix the water and water-reducing agent evenly and divide them into a first mixture and a second mixture with the same mass, and divide the solid waste cementitious material into a first cementitious material and a second cementitious material with the same mass. S2. Mix the large stones, small stones, fine aggregates and the first mixture for 10 seconds, then add the first cementitious material and mix for 30 seconds, then add the second mixture and the second cementitious material and mix for 2 minutes to obtain precast concrete. S3. Pour the precast concrete into a 100mm×100mm×100mm mold, and use a universal press to place it on a concrete vibration table and vibrate and scrape it for 30 seconds according to the requirements for the unconfined compressive strength test of high-performance concrete materials made from all solid waste in the "Technical Specification for Application of High-Performance Concrete Made from All Solid Waste" T / CECS 1254-2023. Then, cure it at 40℃ for 24 hours and demold it to obtain the test block. S4. Place the test block in a standard curing chamber with a temperature of 20±2℃ and a relative humidity of 95% for standard curing to obtain the precast component.

[0042] Comparative Example 1 Except for the fact that the total solid waste cementitious material was 217 parts, i.e. the water-cement ratio was 0.267:1, the other components and preparation methods in this comparative example were the same as in Example 5.

[0043] Comparative Example 2 Except for the water-reducing agent being 1.5 parts and water being 43.5 parts, i.e., the water-to-binder ratio being 0.186:1, the other components and preparation methods in this comparative example are the same as in Example 5.

[0044] Comparative Example 3 Except for the fact that the content of solid waste cementitious material was too low (210.6 parts, 1.8 parts, and 52.2 parts), the other components and preparation methods in this comparative example were the same as in Example 5.

[0045] Comparative Example 4 Except for the blast furnace slag aging time of 2 years, the other components and preparation methods of this comparative example are the same as those of Example 5.

[0046] Comparative Example 5 Except for the steel slag aging time of 3 days, the other components and preparation methods of this comparative example are the same as those of Example 5.

[0047] Comparative Example 6 The only difference between this comparative example and Example 5 is that all the small stones were replaced with large stones.

[0048] Comparative Example 7 Except for the fact that all matrix materials were directly stirred evenly during the preparation of the preform, the other components and preparation methods in this comparative example are the same as those in Example 5.

[0049] The compressive strength of the precast components obtained by curing the specimens of Examples 1-5 and Comparative Examples 1-7 to the target age is shown in Table 1. Table 1 This application proposes a precast marine concrete component made entirely from solid waste and without autoclaving, and its preparation method, which produces the following beneficial effects: Replacing traditional cement with all-solid-waste cementitious materials reduces carbon emissions during cement production and provides an effective resource recovery pathway for steel slag, refining slag, blast furnace slag, and desulfurization gypsum in the metallurgical industry; through the synergistic effect of multiple solid waste materials, its durability is significantly improved compared to traditional cement-based concrete; and by rationally utilizing industrial solid waste, resource consumption and waste emissions are reduced, contributing to sustainable development and providing new ideas for the resource utilization of solid waste in other industries.

[0050] The above description is merely a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made using the content of this application's specification under the inventive concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A precast marine concrete component that does not require steam curing and is made from solid waste, characterized in that, Its matrix materials include: solid waste cementitious materials, large stones, small stones, fine aggregates, water-reducing agents, and water; The mass ratio of the solid waste cementitious material, the large stones, the small stones, and the fine aggregate is (217~234):(321~331):(79~83):(355~368), the water-cement ratio is (0.20~0.26):1, and the mass ratio of water to the water-reducing agent is (24.5~29):

1. The all-solid waste cementitious material uses steel slag, blast furnace slag, refining slag, and desulfurization gypsum as raw materials, and the specific surface area of ​​the all-solid waste cementitious material is greater than 550 m². 2 / kg; The aging time of the steel slag is greater than or equal to 2 months, and the aging time of the blast furnace slag is greater than or equal to 14 days and less than 12 months.

2. The precast marine concrete component without autoclaving as described in claim 1, characterized in that, The mass ratio of the steel slag, blast furnace slag, refining slag, and desulfurized gypsum in the solid waste cementitious material is (20~25):(55~60):(3~5):(13~17).

3. The precast marine concrete component without autoclaving as described in claim 1, characterized in that, The large stones have a diameter greater than 10 mm and less than or equal to 20 mm, and the small stones have a diameter greater than 5 mm and less than or equal to 10 mm.

4. The precast marine concrete component without autoclaving as described in claim 1, characterized in that, The fine aggregate is composed of coarse sand, and the particle size of the fine aggregate is greater than or equal to 0.16 mm and less than or equal to 5 mm.

5. The precast marine concrete component without autoclaving as described in claim 1, characterized in that, The water-reducing agent includes polycarboxylate water-reducing agents.

6. The precast marine concrete component without autoclaving as described in claim 1, characterized in that, The specific preparation method of the all-solid waste cementitious material is as follows: a. Weigh the raw materials and dry them in the dark; b. Grind the dried raw material; c. The ground raw material is sieved to obtain the all-solid waste cementitious material, wherein the specific surface area of ​​the all-solid waste cementitious material is greater than 550 m². 2 / kg.

7. The precast marine concrete component without autoclaving as described in claim 6, characterized in that, The temperature for drying the steel slag, blast furnace slag, and refining slag in the dark is 50~200℃, and the temperature for drying the desulfurized gypsum in the dark is 40~50℃.

8. The precast marine concrete component without autoclaving as described in claim 6, characterized in that, The grinding time is 80-120 minutes.

9. A method for preparing precast marine concrete components without autoclaving as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Weigh out the solid waste cementitious material, large stones, small stones, fine aggregates, and corresponding water and water-reducing agent. Mix the water and water-reducing agent evenly and divide them into a first mixture and a second mixture with the same mass. Divide the solid waste cementitious material into a first cementitious material and a second cementitious material with the same mass. S2. Mix the large stones, small stones, and fine aggregates with the first mixture for 10 seconds, then add the first cementitious material and stir for 30 seconds, then add the second mixture and the second cementitious material and stir for 3-5 minutes to obtain precast concrete. S3. Pour the precast concrete into the mold, vibrate and scrape it for no more than 30 seconds, and cure it according to standard for 24 hours. Then demold the concrete to obtain the test block. S4. The test block is subjected to standard curing for a predetermined time to obtain a precast component.

10. The method for preparing precast marine concrete components without autoclaving according to claim 9, characterized in that, When the predetermined time is 28 days, the compressive strength of the precast component is ≥60MPa.

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