Preparation method of underwater super-retarding concrete
Underwater ultra-retarded concrete is prepared by mixing and heating specific raw materials, which solves the problems of water erosion and separation in underwater construction, and achieves high fluidity and durability of concrete performance, meeting the construction needs of underwater engineering.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QINGDAO HEHUI CONCRETE ENG CO LTD
- Filing Date
- 2024-04-13
- Publication Date
- 2026-07-14
AI Technical Summary
Underwater concrete construction faces challenges such as water erosion, separation, and diffusion, leading to structural inhomogeneity and reduced strength. Existing construction methods are complex, costly, and have significant environmental impacts.
Underwater ultra-retarded concrete is prepared by mixing and heating raw materials such as ethyl acetate, melamine, benzoic anhydride, isocyanate, aluminum lactate, sodium lignosulfonate, and calcium chloride in a specific ratio. This optimizes the cement and aggregate ratio, extends the initial setting time, and improves fluidity and durability.
To improve the water erosion resistance of concrete in underwater environments, maintain high structural strength and durability, meet early construction requirements, and achieve rapid setting.
Smart Images
Figure CN118344089B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, specifically a method for preparing underwater ultra-retarded concrete. Background Technology
[0002] Underwater concrete construction is a crucial technology in modern architecture and civil engineering, particularly in projects such as bridges, tunnels, dams, and harbors. However, underwater concrete construction faces numerous challenges, including the scouring, separation, and diffusion of the concrete slurry by water flow, and the slow strength development during the curing process. These issues lead to inhomogeneity, reduced strength, and compromised durability in the concrete structure. Therefore, developing a method for preparing underwater ultra-retarded concrete is of significant practical importance.
[0003] Traditional underwater concrete is prepared by mixing cement, aggregate, water, and appropriate admixtures in a certain proportion. During underwater construction, special construction methods are usually required to prevent the concrete from being eroded by water currents, such as lowering tremie pipes, using sleeves for pouring, or using concrete with better waterproofing properties. However, these methods have disadvantages such as complex construction, high cost, and significant environmental impact.
[0004] To address these issues, a method for preparing underwater ultra-retarded concrete has been developed. This method aims to improve the concrete's resistance to water erosion, reduce slurry separation and diffusion, and simultaneously ensure the strength development of the concrete during underwater curing. The method involves using special retarders and binders, as well as optimizing the cement and aggregate ratios, to produce concrete with high fluidity, low permeability, and good durability.
[0005] Currently, the preparation of underwater ultra-retarded concrete needs to be considered from the following aspects:
[0006] 1. Raw material selection: Select suitable cement materials, such as silicate cement or sulfoaluminate cement; select clean, hard aggregates with appropriate particle size; and prepare water and admixtures.
[0007] 2. Admixture Formulation: Based on the concrete design requirements, formulate super-retarders and high-efficiency water-reducing agents. Super-retarders extend the initial setting time of concrete, ensuring it does not rapidly harden underwater due to water flow impact; high-efficiency water-reducing agents improve the fluidity and workability of the concrete.
[0008] 3. Uniform mixing: Mix cement, aggregate, water and admixtures in a certain proportion to ensure uniform mixing and form a concrete slurry with good fluidity.
[0009] 4. Placement during construction: Use appropriate construction methods to deliver the concrete slurry to the underwater construction site, and ensure that the slurry does not separate or spread excessively during placement.
[0010] 5. Curing maturity: Under underwater conditions, concrete needs to undergo a period of curing to ensure that the retarder plays its full role and the concrete gradually develops the required strength.
[0011] The underwater ultra-retarded concrete prepared by the above method can not only resist water erosion and reduce environmental pollution, but also maintain high structural strength and durability in underwater construction environments. This preparation method is expected to be widely used in underwater engineering construction. Summary of the Invention
[0012] The purpose of this invention is to provide a method for preparing underwater ultra-retarded concrete. Raw materials such as ethyl acetate, melamine, benzoic anhydride, isocyanate, aluminum lactate, sodium lignosulfonate, and calcium chloride all affect the strength, initial setting time, and final setting time of concrete. Generally, the lower the strength within 3 days, the better it is for the reshaping of underwater concrete materials, meeting certain requirements for concrete fluidity. At the same time, the concrete strength from 7 to 28 days needs to be higher to resist the influence of water and meet the strength performance requirements. In addition, the longer the initial setting time, the better it is for early construction. The smaller the difference between the final setting time and the initial setting time, the better it is for rapid setting. The characteristics shown above meet the specific requirements of underwater ultra-retarded concrete.
[0013] To achieve the above objectives, the present invention provides the following technical solution:
[0014] A method for preparing underwater ultra-retarded concrete includes the following steps:
[0015] Step 1: After crushing bentonite and kaolin, calcine them under high temperature and nitrogen atmosphere to obtain calcined particles. Then, stir the calcined particles, copper sulfate, quicklime and water in a mixer until uniform. After reacting for 6-10 hours, a paste-like viscous mixture is obtained.
[0016] Step 2: Mix sugarcane molasses, ethyl acetate, melamine, polyol, acid anhydride and water, and heat to react to obtain the retarder intermediate;
[0017] Step 3: Mix the paste-like viscous mixture, retarder intermediate, silicate cement, isocyanate, aluminum lactate, sodium lignosulfonate, calcium chloride, and water, pour the mixture into a mold, cure, and then demold to obtain the final product.
[0018] In the above-described method for preparing underwater ultra-slow-setting concrete, the amounts of bentonite and kaolin used in step one are (20kg-40kg) and (50kg-100kg), respectively.
[0019] The high-temperature calcination temperature in step one is 450℃-500℃;
[0020] The high-temperature calcination time in step one is 2-3 hours.
[0021] In the above-described method for preparing underwater ultra-slow-setting concrete, the amounts of calcined granules, copper sulfate, quicklime, aluminum silicate fiber, and water in step one are (30kg-40kg), (5kg-10kg), (5kg-15kg), (6kg-12kg), and (120kg-160kg), respectively.
[0022] In the above-described method for preparing underwater ultra-slow-setting concrete, the amounts of sugarcane molasses, ethyl acetate, melamine, polyol, acid anhydride, and water in step two are (2kg-6kg), (10kg-15kg), (4kg-8kg), (20kg-30kg), (6kg-10kg), and (70kg-100kg), respectively.
[0023] In the above-described method for preparing underwater ultra-retarded concrete, the heating reaction temperature in step two is 95℃-110℃.
[0024] The heating reaction time in step two is 4-8 hours.
[0025] In the above-described method for preparing underwater ultra-slow-setting concrete, the parameters of sugarcane molasses in step two are as follows: sucrose 60% by mass, glucose 25%, fructose 10%, and moisture 5%.
[0026] In step two, the polyol is one of propylene glycol, glycerol, pentaerythritol, or polyethylene glycol.
[0027] In step two, the acid anhydride is one of propionic anhydride, benzoic anhydride, or sulfuric anhydride.
[0028] In the above-described method for preparing underwater super-retarded concrete, the amounts of the paste-like viscous mixture, retarder intermediate, silicate cement, isocyanate, aluminum lactate, sodium lignosulfonate, calcium chloride, and water in step three are (10kg-20kg), (5kg-10kg), (200kg-240kg), (15kg-25kg), (3kg-8kg), (2kg-5kg), (2kg-6kg), and (100kg-140kg), respectively.
[0029] Beneficial effects
[0030] Raw materials such as ethyl acetate, melamine, benzoic anhydride, isocyanate, aluminum lactate, sodium lignosulfonate, and calcium chloride all affect the strength, initial setting time, and final setting time of concrete. Generally, the lower the strength within 3 days, the better it is for underwater concrete materials to be reshaped and to meet certain concrete fluidity requirements. At the same time, the concrete strength from 7 to 28 days needs to be higher to resist the influence of water and meet the strength performance requirements. In addition, the longer the initial setting time, the better it is for early construction. The smaller the difference between the final setting time and the initial setting time, the better it is for rapid setting. The characteristics shown above meet the specific requirements of underwater ultra-retarded concrete.
[0031] These substances have a synergistic effect in underwater super-retarded concrete. Each additive has its specific function, and when they are used in combination, they can complement each other and improve the overall performance of the concrete.
[0032] Ethyl acetate: As a solvent, ethyl acetate may help disperse other additives in concrete, improving the flowability and workability of concrete.
[0033] Melamine: As a retarder, melamine can extend the setting time of concrete, allowing more time for operation and positioning during underwater construction.
[0034] Benzoic anhydride: It may be used as a reaction catalyst or as an additive to adjust the pH value, thereby improving the chemical stability and durability of concrete.
[0035] Isocyanates: commonly used in the preparation of polyurethanes or polyureas to improve the adhesion and elasticity of concrete, and enhance its crack resistance and durability.
[0036] Aluminum lactate: may affect the cement hydration process, improve the early strength and crack resistance of concrete, and reduce alkali-silicic acid reaction (ASR).
[0037] Sodium lignosulfonate: As a water-reducing agent, it improves the fluidity of concrete while reducing the water-cement ratio, thereby increasing the strength and durability of concrete.
[0038] Calcium chloride: As an accelerator, it improves the early strength of concrete and speeds up the construction process, which is especially important in low-temperature environments.
[0039] When these additives are used together, they interact to optimize concrete performance. For example, ethyl acetate helps other additives disperse better in concrete, while the retarding effects of melamine and benzoic anhydride balance the accelerating effect of calcium chloride, ensuring early strength development while extending workable time. Sodium lignosulfonate's water-reducing effect lowers the water-cement ratio without affecting concrete fluidity, while the use of isocyanates and aluminum lactate improves concrete adhesion and durability. This synergistic effect ensures the performance of concrete in underwater construction while meeting the requirements for strength, durability, and workability. Attached Figure Description
[0040] Figure 1 This is a mold design drawing for the test plan. Detailed Implementation
[0041] All reagents involved in this invention are of analytical grade.
[0042] Example
[0043] The preparation method of underwater ultra-retarded concrete includes the following steps:
[0044] Step 1: After crushing bentonite and kaolin, calcinate them under high temperature and nitrogen atmosphere to obtain calcined granules. Then, mix the calcined granules, copper sulfate, quicklime, and water evenly in a mixer and react for 8 hours to obtain a paste-like viscous mixture. The amounts of bentonite and kaolin used in Step 1 are 30 kg and 80 kg, respectively. The calcination temperature in Step 1 is 480℃. The calcination time in Step 1 is 2.5 hours. The quality of bentonite meets the standard of "Bentonite" (GB / T20973-2007), and the quality of kaolin meets the standard of "Kaolin" (GB / T14563-2020). The amounts of calcined granules, copper sulfate, quicklime, aluminum silicate fiber, and water used in Step 1 are 35 kg, 8 kg, 10 kg, 10 kg, and 140 kg, respectively.
[0045] Step Two: Mix cane molasses, ethyl acetate, melamine, pentaerythritol, benzoic anhydride, and water, and heat to react, obtaining a retarding intermediate. The amounts of cane molasses, ethyl acetate, melamine, polyol, anhydride, and water in Step Two are 4 kg, 13 kg, 6 kg, 25 kg, 8 kg, and 80 kg, respectively. The heating temperature in Step Two is 100℃; the heating time in Step Two is 6 hours. The parameters of the cane molasses in Step Two are as follows: sucrose 60% by mass, glucose 25%, fructose 10%, and moisture 5%.
[0046] Step 3: Mix the paste-like viscous mixture, retarder intermediate, silicate cement, isocyanate, aluminum lactate, sodium lignosulfonate, calcium chloride, and water, pour the mixture into a mold, cure, and then demold to obtain the final product. The amounts of the paste-like viscous mixture, retarder intermediate, silicate cement, isocyanate, aluminum lactate, sodium lignosulfonate, calcium chloride, and water in Step 3 are 15 kg, 8 kg, 220 kg, 20 kg, 5 kg, 3 kg, 4 kg, and 120 kg, respectively.
[0047] Comparative Examples 1-5
[0048] Comparative Examples 1-5 provide methods for preparing underwater ultra-retarded concrete. In Comparative Examples 1-5, except for the different proportions of sugarcane molasses, ethyl acetate, melamine, pentaerythritol, and benzoic anhydride, the proportions of other materials and process parameters are the same as in the examples. See Table 1 below:
[0049] Table 1
[0050]
[0051]
[0052] Comparative Examples 6-11
[0053] Comparative Examples 6-11 provide a method for preparing underwater super-retarded concrete. In Comparative Examples 6-11, except for the different proportions of the paste-like viscous mixture, retarder intermediate, isocyanate, aluminum lactate, sodium lignosulfonate, and calcium chloride, the proportions of other materials and process parameters are the same as in the examples, as shown in Table 2 below:
[0054] Table 2
[0055]
[0056] Test Plan
[0057] In this application, the silicate cement is PO 42.5. The ultra-retarded concrete prepared in Examples 1-11 was poured into molds, followed by performance testing after curing and demolding (referencing the testing methods of a collaborating unit, Hu Pengfei. Research and Application of C30 Ultra-Retarded Concrete [D]. Southwest Jiaotong University, 2018. DOI:10.27414 / d.cnki.gxnju.2018.000377.) to meet the requirements of C25 underwater cast-in-place pile concrete. The mold style is as follows. Figure 1 As shown.
[0058] Specific testing methods: Three sets of 100mm×100mm×100mm test blocks were formed, and the concrete surface was covered with a thin film. The blocks were cured in a laboratory at a curing temperature of 20℃±2℃ and a relative humidity of ≥60%. After final setting, the blocks were demolded and cured to the specified age. The concrete strength at 3d, 7d, and 28d was tested according to GB / T 50081, and the setting time was tested according to GB / T50080.
[0059] Table 3
[0060]
[0061]
[0062] As shown in Table 3, raw materials such as ethyl acetate, melamine, benzoic anhydride, isocyanate, aluminum lactate, sodium lignosulfonate, and calcium chloride all affect the strength, initial setting time, and final setting time of concrete. Generally, the lower the strength within 3 days, the better it is for underwater concrete materials to be reshaped and to meet certain concrete fluidity requirements. Meanwhile, the concrete strength from 7 to 28 days needs to be higher to resist the influence of water and meet the strength performance requirements. In addition, the longer the initial setting time, the better it is for early construction. The smaller the difference between the final setting time and the initial setting time, the better it is for rapid setting. The characteristics shown above meet the specific requirements of underwater ultra-retarded concrete. Based on the experiments, the proportions of sugarcane molasses, ethyl acetate, melamine, pentaerythritol, and benzoic anhydride in Comparative Example 1 and Comparative Example 2 were adjusted. The concrete strength decreased, the initial setting time was earlier, and the time interval between the final setting time and the initial setting time was longer. These performance indicators show that the early strength development of the concrete is slow, which helps with reshaping and fluidity during underwater construction. At the same time, the longer initial setting time provides more time for construction operations. However, the longer time interval between the final setting time means that the strength development of the concrete is insufficient for a period of time, and the required final strength needs to be obtained in the later curing stage.
[0063] Comparative Example 3 lacks ethyl acetate. Ethyl acetate, as a solvent or reaction medium, participates in certain chemical reactions in concrete or affects the dispersibility and reactivity of other components in concrete. Its absence leads to reduced concrete fluidity because ethyl acetate helps reduce the mutual attraction between cement particles. Ethyl acetate acts as a reaction medium during cement hydration, which helps improve the workability and fluidity of concrete. The absence of ethyl acetate makes cement particles more prone to aggregation, thereby increasing the viscosity of concrete and affecting its underwater construction performance.
[0064] Comparative Example 4 lacks melamine. Melamine is commonly used as a retarder to extend the initial setting time of concrete. Without melamine, the concrete sets faster, which is detrimental to underwater construction because it requires more time for the concrete to set and solidify. Melamine slows down the hydration rate of cement by reacting with calcium ions in cement to form a stable complex. Without melamine, the hydration rate of cement accelerates, resulting in a shorter initial setting time for the concrete.
[0065] Comparative Example 5 lacks benzoic anhydride. Benzoic anhydride plays a role in regulating the pH value during cement hydration or acts as a catalyst in certain chemical reactions. The absence of benzoic anhydride hinders the chemical reactions in concrete, affecting its final strength development. Benzoic anhydride participates in certain stages of the cement hydration reaction, regulating the reaction rate or altering the microstructure of the hydration products. Without benzoic anhydride, the cement hydration reaction changes, affecting the long-term strength and durability of concrete.
[0066] In the preparation of underwater ultra-retarded concrete, each chemical component has its specific role, and the absence of any one of them will affect the performance of the concrete. Therefore, it is necessary to comprehensively consider the role of various components and meet the special requirements of underwater construction through precise proportioning.
[0067] Meanwhile, in Comparative Examples 6 and 7, the proportions of the paste-like viscous mixture, retarder intermediate, isocyanate, aluminum lactate, sodium lignosulfonate, and calcium chloride were adjusted. Similarly, the concrete strength decreased, the initial setting time became earlier, and the time interval between the final setting and the initial setting time became longer. The adjustment of the proportions of the paste-like viscous mixture, retarder intermediate, isocyanate, aluminum lactate, sodium lignosulfonate, and calcium chloride also caused similar performance changes. The mechanisms of these changes include: retarding effect: sugarcane molasses and other retarder intermediate components react with calcium ions in cement to form stable complexes, delaying the hydration rate of cement and thus prolonging the initial setting time; intermolecular interactions: substances such as ethyl acetate, melamine, and benzoic anhydride affect cement hydration through intermolecular interactions. The microstructure of the cement paste during the process alters its fluidity and setting properties; the heat of hydration affects the concrete by altering the exothermic rate and heat distribution during cement hydration, thus influencing the curing and strength development of the concrete; ionic effects are also present by introducing additional ions, such as sodium lignosulfonate and calcium chloride, which affect the ion concentration gradient of the cement hydration reaction, thereby impacting the initial and final setting times of the concrete; by adjusting the proportions of different raw materials, the performance of concrete during underwater construction can be controlled to meet specific engineering requirements; these adjustments require meticulous control and optimization to ensure that the concrete exhibits good fluidity during underwater construction, sufficient early time for reshaping and repositioning, and sufficient strength in the later stages to resist the effects of the underwater environment.
[0068] Comparative Example 8 lacks isocyanate. Isocyanates are a class of highly reactive compounds that can react with compounds containing active hydrogen (such as alcohols, water, amines, etc.) to form polymers such as polyurethanes or polyureas. In concrete systems, isocyanates can react with water in cement or hydroxyl groups in additives to form a network structure with good elasticity and adhesion. This network structure helps improve the toughness and crack resistance of concrete, especially in extreme underwater environments, where this property is particularly important. When isocyanates are lacking, this isocyanate-induced polymerization reaction cannot occur, and the concrete will lack this elastic network structure. This leads to reduced crack resistance and toughness in concrete, thus affecting its overall durability and long-term performance. Another role of isocyanate in concrete is as a binder, improving the bond strength between concrete and other materials (such as reinforcing steel and aggregate). This bonding effect is crucial for ensuring the integrity of the concrete structure. The absence of isocyanate results in decreased bond strength between concrete and reinforcing steel, increasing the risk of delamination and peeling under stress. Furthermore, the reaction products of isocyanate typically have low permeability, helping to improve the sealing and waterproofing properties of concrete. The absence of isocyanate reduces the sealing performance of concrete, allowing moisture and harmful substances to penetrate more easily. Isocyanates penetrate the concrete interior, accelerating its aging and damage. In underwater concrete construction, workability is a crucial consideration. Because isocyanates improve the fluidity and pumpability of concrete, their absence leads to increased viscosity and reduced fluidity, thus affecting construction efficiency and quality. This is particularly critical in underwater construction, as concrete must possess good fluidity to fill formwork and navigate complex structures. Isocyanates can also improve the self-compacting properties of concrete through their reaction products; their absence reduces the self-compacting capacity of concrete within the formwork, requiring additional vibration and compaction to achieve the desired density and structural performance.
[0069] Compared to Example 9, the absence of aluminum lactate has the following effects on setting time: Aluminum lactate, as a setting time regulator, slows down the hydration process of cement by forming stable complexes with calcium ions in cement. The absence of aluminum lactate leads to a shortened initial and final setting time of concrete, which is detrimental to underwater construction requiring long-term workability. Regarding strength development: Aluminum ions in aluminum lactate affect the nucleation and growth of cement hydration products, contributing to a denser microstructure and thus improving early strength. Without aluminum lactate, the microstructure is not dense enough, resulting in slow strength growth. Regarding workability: As a water-soluble salt, aluminum lactate improves the dispersibility of cement particles and enhances the workability of concrete. The absence of aluminum lactate reduces workability, affecting concrete pouring and molding. Regarding durability: Aluminum compounds help form stable hydration products such as ettringite, which improve concrete durability. The lack of aluminum lactate affects the long-term durability of concrete, especially in harsh underwater environments. It also reduces the alkali-silica reaction (A...). Aluminum ions help reduce the risk of ASR by reacting with active silica in aggregates to form non-expanding products; without aluminum lactate, concrete has an increased risk of ASR, leading to cracking and reduced service life; microstructure refinement: aluminum lactate can act as a microfiller, filling voids in the concrete matrix and refining its microstructure; the lack of aluminum lactate leads to increased porosity and permeability, making concrete more susceptible to erosion by water and chemicals.
[0070] Comparative Example 10: Reduced fluidity due to sodium lignosulfonate deficiency: Without sodium lignosulfonate as a water-reducing agent, the fluidity of concrete decreases, affecting pouring and construction, especially crucial for underwater work where good fluidity is essential; Cement particle agglomeration: Sodium lignosulfonate helps reduce the attraction between cement particles, increasing their dispersion; its absence leads to easier agglomeration of cement particles, forming clumps, which reduces the uniformity and final performance of the concrete; Reduced strength and durability: Since sodium lignosulfonate can improve fluidity without increasing water content, its absence necessitates increased water content to maintain concrete workability, resulting in a higher water-cement ratio and consequently reduced strength and durability; Increased risk of shrinkage and cracking: Sodium lignosulfonate can reduce concrete shrinkage by optimizing particle distribution and reducing water content; without it, concrete exhibits higher drying shrinkage, increasing the risk of cracking.
[0071] Comparative Example 11: Lack of calcium chloride leads to prolonged setting time: The absence of calcium chloride means a slower cement hydration reaction, resulting in prolonged initial and final setting times for concrete. For underwater construction, an excessively long setting time increases the risk of concrete being eroded by water flow and material segregation. Reduced early strength: Calcium chloride improves the early strength of concrete; its absence causes slow strength development in the days following construction, affecting construction progress and subsequent processes. Reduced cold resistance: In low-temperature environments, calcium chloride helps prevent the hydration reaction from ceasing due to excessively low temperatures. Without calcium chloride, the curing and strength development of concrete in cold environments are affected. Durability issues: While calcium chloride improves early strength, it also leads to steel corrosion and reduced concrete durability. Therefore, the absence of calcium chloride reduces these negative effects to some extent, but also negates the positive effects it provides.
[0072] The preferred embodiments of this patent have been described in detail above. However, this patent is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this patent.
Claims
1. A method for preparing underwater ultra-retarded concrete, characterized in that, Includes the following steps: Step 1: After crushing bentonite and kaolin, calcine them under high temperature and nitrogen atmosphere to obtain calcined granules. Then, mix the calcined granules, copper sulfate, quicklime, aluminum silicate fiber, and water in a mixer until homogeneous. After reacting for 6-10 hours, a paste-like viscous mixture is obtained. The amounts of calcined granules, copper sulfate, quicklime, aluminum silicate fiber, and water in Step 1 are (30kg-40kg), (5kg-10kg), (5kg-15kg), (6kg-12kg), and (120kg-160kg), respectively. Step 2: Mix sugarcane molasses, ethyl acetate, melamine, polyol, acid anhydride, and water, and heat to react to obtain a retarder intermediate. Step 3: Mix the paste-like viscous mixture, retarder intermediate, silicate cement, isocyanate, aluminum lactate, sodium lignosulfonate, calcium chloride, and water, pour into a mold, cure, and demold to obtain the final product.
2. The method for preparing underwater ultra-retarded concrete according to claim 1, characterized in that, In step one, the amounts of bentonite and kaolin used are (20kg-40kg) and (50kg-100kg) respectively; the calcination temperature in step one is 450℃-500℃; and the calcination time in step one is 2h-3h.
3. The method for preparing underwater ultra-retarded concrete according to claim 2, characterized in that, In step two, the amounts of sugarcane molasses, ethyl acetate, melamine, polyol, acid anhydride and water used are (2kg-6kg), (10kg-15kg), (4kg-8kg), (20kg-30kg), (6kg-10kg), and (70kg-100kg), respectively.
4. The method for preparing underwater ultra-retarded concrete according to claim 3, characterized in that, The heating temperature in step two is 95℃-110℃; the heating time in step two is 4h-8h.
5. The method for preparing underwater ultra-retarded concrete according to claim 4, characterized in that, The parameters of the sugarcane molasses in step two are as follows: sucrose 60% by mass, glucose 25%, fructose 10%, and moisture 5%; the polyol in step two is one of propylene glycol, glycerol, pentaerythritol, and polyethylene glycol; the acid anhydride in step two is one of propionic anhydride, benzoic anhydride, and sulfuric anhydride.
6. The method for preparing underwater ultra-retarded concrete according to claim 5, characterized in that, In step three, the amounts of the paste-like viscous mixture, the retarder intermediate, silicate cement, isocyanate, aluminum lactate, sodium lignosulfonate, calcium chloride, and water are (10kg-20kg), (5kg-10kg), (200kg-240kg), (15kg-25kg), (3kg-8kg), (2kg-5kg), (2kg-6kg), and (100kg-140kg), respectively.