Steam-curing-free precast concrete low-carbon early-strength water reducing agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of building materials, and discloses a steam-curing-free prefabricated concrete low-carbon early-strength water reducing agent which comprises the following components in parts by weight: 50-60 parts of a WPC1000-series polycarboxylic acid water reducing agent; 7 to 9 parts of sodium gluconate; 10 to 15 parts of nano silicon dioxide powder; 1 to 2 parts of perovskite type perovskite; 5-10 parts of slag powder or fly ash; the invention further provides a preparation method of the steam-curing-free precast concrete low-carbon early-strength water reducing agent and application of the steam-curing-free precast concrete low-carbon early-strength water reducing agent. By introducing the low-carbon mineral admixture, the nano silicon dioxide and the perovskite photocatalyst, the early strength of the concrete is improved, the carbon emission is reduced, the concrete is endowed with a self-cleaning function, and the dual goals of environmental protection and efficient construction are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and particularly to a low-carbon early-strength water reducer for steam-curing-free precast concrete, its preparation method and application. Background Art

[0002] With the development of modern construction industry, the requirements for building materials are becoming increasingly strict. As the most widely used basic material in the construction industry, the performance of concrete directly affects the quality, structural safety and service life of buildings. With the increasingly strict environmental protection regulations, the construction industry urgently needs a new concrete solution that can improve the early strength of concrete while reducing energy consumption and carbon emissions.

[0003] Currently, many traditional concrete formulations use polycarboxylate water reducers and retarders to improve the fluidity and early strength of concrete. Some technologies also reduce the amount of cement used by introducing low-carbon materials such as slag powder and fly ash, thereby reducing carbon emissions. These technologies have effectively improved the compressive strength and impermeability of concrete, and have been widely used especially in the field of low-carbon environmental protection. Through the optimization of the formulation, traditional water reducers have achieved certain results in improving the fluidity of concrete and enhancing its later strength.

[0004] However, there are still some deficiencies in the existing technologies in practical applications; firstly, although traditional water reducers can improve fluidity and later strength, their effect of improving early strength at normal temperature is limited, and they cannot meet the requirements of steam-curing-free concrete. Steam curing is still a necessary step in many production processes, which easily leads to high energy consumption and high carbon emissions; secondly, although existing low-carbon concrete formulations reduce the amount of cement used, they often sacrifice the early strength of concrete, affecting the construction efficiency; thirdly, although some existing technologies consider anti-pollution, pollutants are still likely to accumulate on the concrete surface, and the cleaning cost is high, and the self-cleaning function cannot be truly realized. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technologies, the present invention provides a low-carbon early-strength water reducer for steam-curing-free precast concrete, its preparation method and application, and solves the problems of improving the early strength of concrete at normal temperature, reducing carbon emissions and realizing the self-cleaning function in the existing technologies.

[0006] To achieve the above purposes, the present invention is realized through the following technical solutions: A low-carbon early-strength water reducer for steam-curing-free precast concrete, the water reducer comprises the following components in parts by weight: WPC1000 series polycarboxylate superplasticizer: 50 - 60 parts. The mechanism of polycarboxylate superplasticizer is mainly reflected in the characteristics of its molecular structure. Polycarboxylate superplasticizer usually consists of a polymer chain with hydrophilic groups (such as carboxyl groups) and hydrophobic groups (such as olefin groups). Its hydrophilic groups can interact with the surface of cement particles, reducing the cohesion between cement particles, enhancing the dispersibility of cement paste, and thus improving the fluidity of concrete; Sodium gluconate: 7 - 9 parts. As a retarder, sodium gluconate can, during the reaction of cement with water, form a protective film by the action of its carboxyl groups in the molecule on the cement surface, slowing down the rapid reaction during the cement hydration process. Through this mechanism, sodium gluconate can extend the initial time of cement hydration, enabling the workability of cement paste to be maintained for a longer time; Nano - silica powder: 10 - 15 parts. Nano - silica has a very high specific surface area and reactivity, and can participate in the secondary hydration reaction during the hydration process of concrete. Its fine particle size enables it to effectively fill the micro - pores between cement particles, reducing the porosity, and thus enhancing the density and impermeability of concrete. In addition, nano - silica can react with calcium hydroxide in the cement hydration products to form additional hydration products (such as C - S - H gel), further enhancing the strength of concrete; Perovskite - type perovskite: 1 - 2 parts. The mechanism of perovskite - type photocatalyst is based on its special crystal structure, which can excite electrons under light illumination to form electron - hole pairs, thereby driving redox reactions. Through these reactions, perovskite - type photocatalysts can effectively decompose harmful gases in the air (such as formaldehyde, benzene, NOx, etc.), thus realizing the self - purification function. In addition, these photocatalytic reactions can also decompose stains and pollutants on the concrete surface, keeping the concrete surface clean; Ground granulated blast - furnace slag or fly ash: 5 - 10 parts. Ground granulated blast - furnace slag and fly ash react with cement during the cement hydration process to form secondary hydration products, such as C - S - H gel, further improving the microstructure of concrete. By replacing a part of cement, these mineral admixtures can reduce the cement consumption, thereby reducing carbon emissions. In addition, the addition of ground granulated blast - furnace slag and fly ash can also increase the chemical corrosion resistance, freeze - thaw resistance and impermeability of concrete, enhancing its durability; Water: 20 - 30 parts. Water reacts with cement to form calcium hydroxide and continues to form C - S - H gel on this basis. The amount of water directly determines the process of cement hydration reaction and the workability of concrete. In this scheme, the introduction of polycarboxylate superplasticizer reduces the amount of water used, optimizes the ratio of water to cement, thereby improving the efficiency of cement hydration reaction and enhancing the early strength of concrete.

[0007] The present invention also provides a preparation method of a steam - curing - free precast concrete low - carbon early - strength superplasticizer, including the following steps: Step 1: Raw material preparation: Prepare all the required raw materials, including WPC1000 series polycarboxylate superplasticizer, sodium gluconate, nano-silica powder, perovskite-type perovskite, and slag powder or fly ash, as well as water, and ensure that the pretreatment and preparation of the raw materials meet the usage requirements; Step 2: Mixing: Add an appropriate amount of water to the mixer and sequentially add the above-mentioned raw materials. By controlling the mixing speed and mixing time, ensure that each component is fully mixed and a uniform slurry is formed. The main purpose of the mixing process is to ensure the uniform dispersion and full reaction of the raw materials. During this process, the interaction between the polycarboxylate superplasticizer and the surface of cement particles helps to reduce the cohesion between cement particles and improve the fluidity of the cement paste. Sodium gluconate, as a retarder, forms a layer of relief film by reacting with the cement surface, delaying the cement hydration reaction and ensuring the persistence and stability of cement hydration. Due to its extremely large specific surface area and high reactivity, nano-silica powder can react with calcium hydroxide in cement during the mixing process to generate additional hydration products (C-S-H), enhancing the denseness of the concrete. The perovskite-type photocatalyst will also physically adsorb with the cement paste during the mixing process to ensure its uniform dispersion and maintain good photocatalytic effect. Slag powder or fly ash can form new hydration products with cement hydration products during mixing, improving the frost resistance, impermeability and other properties of the concrete; Step 3: Temperature control: During the mixing process, use a temperature control system to control the mixing temperature to ensure that the cement hydration reaction can proceed under ideal temperature conditions, and avoid the influence of too high or too low temperature on the reaction rate. A lower temperature will slow down the cement hydration reaction rate, while too high a temperature may cause the cement to hydrate too quickly, resulting in insufficient early strength and unstable structure of cement particles. Adjust the mixing temperature through the temperature control system to ensure that it proceeds at the ideal reaction temperature, which helps to promote the uniformity and stability of cement hydration. The effectiveness of temperature control is to ensure that the retarder (such as sodium gluconate) in the superplasticizer can play a role within an appropriate time, while avoiding the negative impact of temperature fluctuations on the reaction rate and concrete strength; Step 4: pH value adjustment: Adjust the pH value of the mixed solution to an appropriate range to promote the smooth progress of the cement hydration reaction and ensure the stability of the superplasticizer during subsequent use. Too low or too high pH value may affect the formation of cement hydration products, thereby affecting the strength and stability of the concrete. By controlling the pH value, it can ensure that the cement hydration reaction proceeds under the best conditions, promoting the formation of C-S-H gel, thereby effectively improving the early strength of the concrete. In addition, the adjustment of the pH value also helps to ensure the stability of the superplasticizer and prevent it from undergoing chemical denaturation during storage and use; Step 5: Standing and Filtration: After stirring is completed, let it stand for a certain period of time to ensure that the materials react fully. Subsequently, filter out the undissolved impurities to ensure the quality and stability of the final water reducer. The setting of the standing time is to allow the components in the water reducer to react fully, especially the reaction between cement and nano materials, retarders, etc. Through standing, the fine particles in the solution can aggregate and precipitate, ensuring a complete reaction. The role of the filtration step is to remove the unreacted impurities and insoluble substances to prevent these impurities from affecting the stability and later effects of the water reducer. Through standing and filtration, ensure that the finally obtained water reducer has high purity, stability, and strong functionality; Step 6: Storage and Packaging: Store the finally prepared water reducer in a sealed manner. After it cools down and stabilizes, carry out packaging for subsequent use. By sealing and packaging and controlling the storage temperature and humidity, these external factors can be effectively avoided from affecting the water reducer, ensuring the long-term stability of the water reducer. In addition, the selection of packaging materials is also very important. Using polyethylene film and containers that meet food-grade or chemical packaging standards can prevent the intrusion of external pollutants and maintain the purity of the water reducer.

[0008] Preferably, the stirring step includes: Put water and water reducer raw materials into a stirrer and start stirring; Add other materials in sequence. Control the stirring time within 30 - 45 minutes and the stirring speed within 500 - 1500 revolutions per minute. The control of the stirring speed affects the uniformity and mixing efficiency of stirring. At a lower rotational speed, the dispersion effect of the materials is poor, which may lead to material aggregation. While at a higher rotational speed, although the dispersion effect is better, it may cause the generation of bubbles. Therefore, controlling the rotational speed within the range of 500 - 1500 revolutions per minute is an ideal choice to ensure uniform dispersion of the materials without generating bubbles. This process ensures that the components in the water reducer (such as nano-silica, retarder, and photocatalyst, etc.) can be effectively dispersed in the cement paste, fully contact with the cement particles, and participate in the hydration reaction; The control of the stirring time (30 - 45 minutes) can ensure full reaction between the materials. Especially for water reducers of polymer type and powder materials such as slag powder and fly ash, extending the stirring time helps them carry out secondary hydration reactions during the cement hydration process. The stirring time of this step not only helps reduce the agglomeration between cement particles but also ensures that materials such as nano-silica and photocatalyst can be evenly distributed in the concrete paste, avoiding the aggregation and uneven distribution of large particles.

[0009] Preferably, the temperature control step includes ensuring, through a temperature control system, that the temperature during the stirring process remains between 20 - 30°C. At lower temperatures, the hydration rate of cement is slow, and the degree of hydration of cement particles is insufficient, resulting in slow early strength development of concrete. At excessively high temperatures, the cement hydration reaction is too intense, which may lead to too rapid a reaction, the formation of unstable hydration products, and the final strength of the concrete may be affected. Within the suitable range of 20 - 30°C, it can ensure that the cement hydration reaction proceeds at an appropriate rate, making the process of cement hydration balanced and effectively enhancing the early strength. By maintaining the temperature between 20 - 30°C, it ensures that the water-reducing agent and retarder are in the best reaction conditions, promotes the formation of cement hydration products, improves the utilization rate of cement, and ensures the strength, fluidity, and later durability of the concrete; Polycarboxylate water-reducing agent and retarder (such as sodium gluconate) have a certain regulatory effect on the cement hydration reaction. At lower temperatures, the effect of the water-reducing agent may not be fully exerted because the hydration reaction of cement is slow. At higher temperatures, the too rapid hydration reaction may inhibit the action of the water-reducing agent, especially the effect of the retarder will be consumed, resulting in the failure of the water-reducing agent. The hydration reactions of slag powder and fly ash are usually slow, especially at low temperatures, and their reaction activities are inhibited, which may lead to slow growth of concrete strength. By controlling the stirring temperature between 20 - 30°C, the activities of slag and fly ash can be stimulated, the reaction efficiency with cement can be improved, and thus the overall performance of the concrete can be optimized.

[0010] Preferably, the pH value adjustment step includes: adjusting the pH to the range of 7.5 - 8.5 by adding acid or alkali to promote the stability of the water-reducing agent and the smooth progress of the cement hydration reaction. By controlling the pH value within the range of 7.5 - 8.5, the rate of the cement hydration reaction can be optimized, the stability of the water-reducing agent can be ensured, and the synergistic effect between cement and various functional materials (such as nano-silica, photocatalyst, etc.) can be promoted, thereby enhancing the early strength, fluidity, durability, and environmental protection performance of the concrete. The adjustment of the pH value ensures the best progress of the cement hydration reaction and at the same time guarantees the efficient use of the water-reducing agent and other functional additives, so that the final product has better performance and stability.

[0011] Preferably, the standing and filtration step includes: Let the stirred mixture stand for 2 hours to ensure full reaction. During the standing period, the molecular chains in the polycarboxylate water-reducing agent will continue to act on the cement particles to produce stable cement hydration products. At the same time, retarders such as sodium gluconate will also continue to delay the premature hydration reaction of cement. Through this process, the concrete can finally obtain relatively uniform strength development and fluidity; After standing, the undissolved impurities are removed through a filter to ensure the purity of the final water-reducing agent material. Filtration can not only remove large-particle impurities but also avoid the influence of small bubbles or precipitates that may be generated during the stirring process on the final performance of the concrete. Especially when using materials such as nano-silica, it is crucial to ensure its uniform dispersion. Therefore, the filtration step can effectively remove any undissolved materials, ensuring the high purity, stability, and efficiency of the finally prepared water-reducing agent.

[0012] Preferably, the storage and packaging steps include: The finally prepared water-reducing agent is filled into a standard sealed container, ensuring that the container material is suitable for long-term storage, preventing contact with moisture or pollutants in the air, and avoiding deterioration of the water-reducing agent. The storage environment should be controlled within the temperature range of 20°C - 30°C and the relative humidity should be kept below 50%. At the same time, ensure good ventilation in the storage space to avoid the influence of high temperature, high humidity, and direct sunlight on the water-reducing agent. By using a sealed container, controlling the temperature and humidity of the storage environment, maintaining good ventilation, and avoiding direct sunlight, the stability, purity, and efficiency of the water-reducing agent during storage are ensured.

[0013] Preferably, the storage and packaging steps further include: Before packaging, use a polyethylene film to prevent the water-reducing agent from reacting with moisture in the air, which may cause changes in its properties and affect the use effect. The polyethylene film is a material with good moisture-proof performance and strong sealing property, which can effectively isolate moisture in the air. Water-reducing agents, especially polycarboxylate-based high-performance water-reducing agents, are extremely sensitive to moisture. The absorption of moisture may lead to the degradation or structural changes of the molecular chain, thereby affecting its affinity with cement particles and weakening its water-reducing effect. During the packaging process, use a sealed container that meets the food-grade or chemical packaging standard to prevent moisture and impurities in the air from entering and ensure the purity of the product. Selecting a sealed container that meets the food-grade or chemical packaging standard can effectively prevent external impurities, moisture in the air, and harmful substances from entering the water-reducing agent packaging. Food-grade or chemical packaging materials usually have high chemical stability and physical isolation ability, which can prevent pollution or property changes of the water-reducing agent caused by the external environment. When closing the container, ensure that the seal is tight to avoid leakage or air entry during transportation and storage. A tight seal is crucial during the packaging process. Water-reducing agents, especially polycarboxylate water-reducing agents, are usually very sensitive to changes in environmental conditions (such as temperature and humidity). Loose sealing may cause moisture or oxygen to penetrate, resulting in the degradation or performance decline of the water-reducing agent. By ensuring the tightness of the container seal, it can be guaranteed that the water-reducing agent is not affected by external factors during transportation and storage and maintains its stable function.

[0014] The present invention also provides the application of a low-carbon early-strength water reducer for precast concrete without steam curing. The water reducer is applied to precast concrete and is particularly suitable for the production of precast concrete under conditions without steam curing.

[0015] The present invention provides a low-carbon early-strength water reducer for precast concrete without steam curing, its preparation method and application. It has the following beneficial effects: 1. By introducing low-carbon mineral admixtures such as slag powder and fly ash, the present invention reduces the cement consumption and carbon emissions. Compared with traditional formulations, the present invention effectively reduces carbon dioxide emissions, promotes the progress of green buildings, not only protects the environment but also realizes the efficient utilization of resources.

[0016] 2. The innovative formulation of combining the polycarboxylate water reducer of the present invention with nano-silica significantly improves the early strength of concrete. Traditional solutions often rely on steam curing to harden quickly, while the present invention can rapidly enhance the strength at normal temperature, reducing energy consumption and curing time.

[0017] 3. By adding a perovskite-type photocatalyst, the present invention endows the concrete with self-cleaning function to help remove surface pollution. This innovation enables the concrete to remain clean after long-term use, reducing the maintenance requirements. Compared with traditional formulations, the present invention not only improves the durability but also takes into account the environmental benefits.

[0018] 4. By controlling the pH value and temperature, the present invention ensures the stability of the water reducer in concrete and improves the efficiency of cement hydration reaction. This refined technical control makes the quality of concrete more stable, avoids performance fluctuations caused by incomplete reactions in conventional formulations, and significantly improves the consistency and long-term performance of the finished products. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flowchart of the method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the specification of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Please refer to the attached Figure 1 : Example 1: Comparison between the conventional formulation and the formulation of the present invention Materials: WPC1000 series polycarboxylate water reducer: 55 parts; Sodium gluconate: 8 parts; Nano-silica powder: 12 parts; Perovskite-type perovskite: 1.5 parts; Slag powder: 7 parts; Water: 25 parts; Steps: Pour water and polycarboxylate superplasticizer into a stirrer, start the stirrer, and set the speed to 800 revolutions per minute.

[0022] Add sodium gluconate, nano-silica powder, perovskite-type perovskite, and slag powder in sequence, and control the stirring time to 40 minutes.

[0023] During the stirring process, use a temperature control system to ensure that the temperature of the mixed liquid remains at about 25°C to avoid too fast or too slow reaction rate.

[0024] After the stirring is completed, let the mixed liquid stand for 2 hours to ensure that all components react completely.

[0025] Filter with a fine filter to remove any undissolved particles and ensure the purity of the final superplasticizer.

[0026] Store the filtered superplasticizer in a sealed container, ensure good sealing, avoid air or moisture from entering, and set the storage conditions at 20°C - 30°C with a humidity not exceeding 50%.

[0027] Example 2: Low-carbon and environmentally friendly formulation Materials: WPC1000 series polycarboxylate superplasticizer: 60 parts; Sodium gluconate: 7 parts; Nano-silica powder: 13 parts; Perovskite-type perovskite: 1 part; Fly ash: 6 parts; Water: 22 parts; Steps: Put 22 parts of water and 60 parts of polycarboxylate superplasticizer into a stirrer, and set the stirring speed to 1000 revolutions per minute.

[0028] Add 7 parts of sodium gluconate to the stirrer. After ensuring its complete dissolution, add 13 parts of nano-silica powder.

[0029] Continue to add 1 part of perovskite-type photocatalyst and 6 parts of fly ash, and set the stirring time to 35 minutes.

[0030] During the stirring process, the temperature control system automatically adjusts the temperature to remain at 23°C to ensure the stability of the reaction rate.

[0031] Let it stand for 2 hours to allow all components to react fully.

[0032] Filter the mixture to remove unreacted particles and ensure the purity of the final water reducer.

[0033] Put the water reducer into a sealed container, control the storage temperature at 25 °C, and keep the relative humidity below 45%.

[0034] Example 3: Comparison between traditional high-carbon emission formula and the formula of the present invention Materials: WPC1000 series polycarboxylate water reducer: 58 parts; Sodium gluconate: 8 parts; Nano-silica powder: 11 parts; Perovskite-type perovskite: 1.2 parts; Water: 26 parts; Steps: Add 26 parts of water and 58 parts of WPC1000 series polycarboxylate water reducer to the stirrer, start stirring, and set the rotation speed to 1200 revolutions per minute.

[0035] Add 8 parts of sodium gluconate and continue stirring for 10 minutes to ensure complete dissolution.

[0036] Add 11 parts of nano-silica powder and 1.2 parts of perovskite-type photocatalyst in sequence, and control the stirring time at 40 minutes.

[0037] Set the temperature to 24 °C, and ensure the temperature stability during stirring to prevent the reaction from being too fast or too slow.

[0038] Let it stand for 2 hours to ensure complete chemical reaction.

[0039] Remove the particulate matter in the mixture by filtration to ensure the high purity of the water reducer.

[0040] Store the water reducer in a sealed container, maintain the storage temperature at 25 °C, and the humidity does not exceed 50%.

[0041] Example 4: High-performance environmental protection formula Materials: WPC1000 series polycarboxylate water reducer: 56 parts; Sodium gluconate: 8.5 parts; Nano-silica powder: 14 parts; Perovskite-type perovskite: 1 part; Slag powder: 8 parts; Water: 23 parts; Steps: Add 23 parts of water and 56 parts of WPC1000 series polycarboxylate water reducer to the stirrer, set the stirring speed to 1000 revolutions per minute, and start stirring.

[0042] Add 8.5 parts of sodium gluconate and continue stirring until it is completely dissolved.

[0043] Add 14 parts of nano-silica powder and continue stirring to ensure the powder is evenly dispersed.

[0044] Add 1 part of perovskite photocatalyst and 8 parts of slag powder, and control the stirring time to 45 minutes.

[0045] Keep the temperature during stirring at 25 °C, monitor it using a temperature control system to ensure the stirring temperature is stable.

[0046] Let it stand for 2 hours to ensure that all reactions proceed fully.

[0047] Filter the mixed solution to remove impurities and ensure the purity of the final water reducer.

[0048] Store it in a sealed container, control the storage temperature at 20 - 30 °C, and the humidity not exceeding 50%.

[0049] Comparative Example 1: Comparison between the traditional single polycarboxylate water reducer formula and the formula of the present invention Materials: WPC1000 series polycarboxylate water reducer: 60 parts; Sodium gluconate: 8 parts; Water: 32 parts; Steps: Add 32 parts of water and 60 parts of polycarboxylate water reducer into a stirrer.

[0050] Start stirring, and set the stirring speed at 1000 revolutions per minute.

[0051] Add 8 parts of sodium gluconate and continue stirring until completely dissolved.

[0052] Control the stirring time to 40 minutes to ensure that the ingredients are fully and evenly mixed.

[0053] After completing the stirring, let it stand for 30 minutes to allow the materials to react fully.

[0054] Filter to remove undissolved impurities to ensure the purity of the final water reducer.

[0055] Store it in a sealed container at room temperature with the humidity not exceeding 50%.

[0056] Comparative Example 2: Comparison between the traditional formula without slag powder or fly ash and the formula of the present invention Materials: WPC1000 series polycarboxylate water reducer: 58 parts; Sodium gluconate: 7 parts; Nano-silica powder: 12 parts; Perovskite-type perovskite: 1.2 parts; Water: 26 parts Steps: Add 26 parts of water and 58 parts of polycarboxylate superplasticizer into a stirrer.

[0057] Start stirring, and set the stirring speed to 900 revolutions per minute to ensure uniform mixing of water and superplasticizer.

[0058] Gradually add 7 parts of sodium gluconate and stir for 10 minutes to ensure its complete dissolution.

[0059] Add 12 parts of nano-silica powder and continue stirring to ensure uniform dispersion.

[0060] Add 1.2 parts of perovskite-type perovskite and continue stirring for 20 minutes.

[0061] Control the temperature at 23 °C and adjust it using a temperature control system.

[0062] Let it stand for 1 hour to ensure sufficient reaction of the materials.

[0063] Filter to remove impurities and ensure the purity of the final superplasticizer.

[0064] Store it in a sealed container, ensure a stable storage environment, with a temperature of 25 °C and a humidity not exceeding 50%.

[0065] Comparative Example 3: Comparison between the traditional high-cement-usage formula and the formula of the present invention Materials: WPC1000 series polycarboxylate superplasticizer: 65 parts; Sodium gluconate: 7.5 parts; Water: 30 parts; Nano-silica powder: 10 parts; Perovskite-type perovskite: 1 part; Steps: Add 30 parts of water and 65 parts of polycarboxylate superplasticizer into a stirrer and start stirring.

[0066] Add 7.5 parts of sodium gluconate and stir until it is completely dissolved.

[0067] Add 10 parts of nano-silica powder and stir for 20 minutes to ensure its uniform dispersion.

[0068] Add 1 part of perovskite-type photocatalyst and continue stirring for 30 minutes.

[0069] Use a temperature control system to adjust the temperature to 24 °C to ensure stable reaction.

[0070] Let it stand for 2 hours to ensure sufficient reaction.

[0071] Filter to remove impurities and ensure the purity of the superplasticizer.

[0072] Stored in a standard sealed container, the storage temperature is maintained at 25 °C and the humidity is below 50%.

[0073] Comparative Example 4: Comparison between a traditional formula without nano-silica and the formula of the present invention Materials: WPC1000 series polycarboxylate superplasticizer: 60 parts; Sodium gluconate: 8 parts; Water: 28 parts; Perovskite-type perovskite: 1 part; Ground granulated blast-furnace slag: 8 parts; Steps: Add 28 parts of water and 60 parts of polycarboxylate superplasticizer into a stirrer, and set the stirring speed to 1100 revolutions per minute.

[0074] Add 8 parts of sodium gluconate and continue stirring until completely dissolved.

[0075] Gradually add 8 parts of ground granulated blast-furnace slag and stir for 35 minutes to ensure its uniform dispersion.

[0076] Add 1 part of perovskite-type photocatalyst and continue stirring for 30 minutes.

[0077] Keep the temperature at 24 °C to ensure the stability of the stirring process.

[0078] Let it stand for 1 hour to ensure complete reaction of the materials.

[0079] Filter to remove impurities to ensure the purity of the superplasticizer.

[0080] Stored in a sealed container, the temperature is controlled at 23 °C and the humidity is maintained below 40% Comparative experiment: Experimental steps and materials In this experiment, we will compare the effects of superplasticizers with different formulas on the performance of concrete, and focus on testing the early strength, carbon emissions, durability (freeze-thaw resistance, impermeability) and self-cleaning function. The following are the specific experimental procedures and material preparations.

[0081] Early strength test: Experimental materials: Example 1 (formula of the present invention); Comparative Example 1 (traditional single polycarboxylate superplasticizer formula); Steps: Prepare a standard formula and mix it into concrete according to the process.

[0082] Pour the concrete into a standard test mold (100 mm × 100 mm × 100 mm), take it out after standing for 24 hours.

[0083] After 7 days and 28 days, the compressive strength of the specimens was tested using a compressive testing machine.

[0084] Each formulation was tested 3 times repetitively and the average value was taken.

[0085] Carbon emission test: Experimental materials: Example 2 (low-carbon and environmentally friendly formulation); Comparative Example 2 (traditional formulation without slag powder or fly ash); Steps: Prepare the water-reducing agent according to the process and calculate the carbon emission per ton of concrete.

[0086] Using the test method of ISO14064 standard, measure the carbon dioxide emission per ton of concrete during the production process.

[0087] Measure the difference in emissions before and after, and record the carbon emission per ton of concrete.

[0088] Durability test: Experimental materials: Example 3 (high-performance and environmentally friendly formulation); Comparative Example 3 (traditional formulation with high cement dosage); Steps: Prepare concrete specimens of 30 cm × 30 cm × 30 cm and cure them for 28 days.

[0089] Conduct freeze-thaw cycle resistance tests (50 freeze-thaw cycles) and impermeability tests respectively.

[0090] Use standard freeze-thaw equipment to conduct 50 freeze-thaw cycles and record the strength loss.

[0091] Test the impermeability performance under water pressure and record the water penetration depth.

[0092] Self-cleaning ability test: Experimental materials: Example 4 (formulation introducing perovskite photocatalyst); Comparative Example 4 (traditional formulation without photocatalyst); Steps: Prepare standard concrete slabs (100 cm × 100 cm) and produce them using the formulations of the present invention and the comparative examples.

[0093] Expose the slabs to sunlight and observe the removal effect of surface pollutants (such as formaldehyde, NOx, etc.).

[0094] Record the change in pollutant concentration and test the degradation rate of surface harmful substances using environmental monitoring equipment.

[0095] Comparison of Experimental Data between Examples 1-4 and Comparative Examples 1-4 Experimental Summary: First of all, in terms of early strength, the examples of the present invention have a significant improvement compared with the traditional formula, especially in the compressive strength at 7 days and 28 days. This is mainly attributed to the introduction of slag powder and nano-silica in the formula of the present invention, which not only improve the hydration efficiency of cement, but also promote the densification of the concrete microstructure, enabling the rapid growth of the early strength of the concrete.

[0096] Secondly, in the comparison of carbon emissions, the present invention effectively reduces carbon dioxide emissions by replacing cement with low-carbon materials (such as slag powder and fly ash). Compared with the traditional formula, the present invention reduces the carbon footprint in the concrete production process and has obvious environmental protection advantages. This result verifies the contribution of the present invention in meeting the global carbon emission reduction target.

[0097] In terms of durability, the experimental results show that the examples in the present invention are also superior to the traditional formula in terms of freeze-thaw cycle resistance and impermeability. Especially in terms of freeze-thaw resistance, the examples of the present invention show a higher strength retention rate, indicating that it is more suitable for use under extreme climate conditions.

[0098] Finally, the test results of the self-cleaning ability show that the perovskite photocatalyst in the formula of the present invention enables the concrete to have a self-cleaning function, which can effectively decompose surface pollutants and maintain its surface cleanliness and environmental friendliness. This innovative function is completely absent in the traditional formula, demonstrating the unique advantages of the present invention.

[0099] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A precast concrete low-carbon early-strength water reducer without steam curing, characterized in that, The water reducing agent comprises the following components in parts by weight: WPC1000 series polycarboxylate water reducing agent: 50 - 60 parts; Sodium gluconate: 7 - 9 parts; Nano-silica powder: 10 - 15 parts; Perovskite-type perovskite: 1 - 2 parts; Slag powder or fly ash: 5 - 10 parts; Water: 20 - 30 parts.

2. Preparation method of non-steam-cured precast concrete low-carbon early-strength water reducing agent, characterized in that, Using the steam-curing-free precast concrete low-carbon early-strength water reducing agent described in claim 1, it includes the following steps: Step 1: Raw material preparation: Prepare all the required raw materials, including WPC1000 series polycarboxylate water reducing agent, sodium gluconate, nano-silica powder, perovskite-type perovskite, slag powder or fly ash, and water, and ensure that the pretreatment and preparation of the raw materials meet the usage requirements; Step 2: Stirring: Add an appropriate amount of water into the stirrer, and sequentially add the above raw materials. By controlling the stirring speed and time, ensure that each component is fully mixed and a uniform slurry is formed; Step 3: Temperature control: During the stirring process, use a temperature control system to control the mixing temperature to ensure that the cement hydration reaction can proceed under ideal temperature conditions and avoid the influence of too high or too low temperature on the reaction rate; Step 4: pH value adjustment: Adjust the pH value of the mixed solution to a suitable range to promote the smooth progress of the cement hydration reaction and ensure the stability of the water reducing agent during subsequent use; Step 5: Standing and filtration: After stirring is completed, stand for a certain period of time to ensure that the materials react fully; subsequently, remove the undissolved impurities by filtration to ensure the quality and stability of the final water reducing agent; Step 6: Storage and packaging: Store the finally prepared water reducing agent in a sealed manner. After it cools down and stabilizes, carry out packaging for subsequent use.

3. The preparation method of the steam-curing-free precast concrete low-carbon early-strength water reducing agent according to claim 2, characterized in that, The said stirring step includes: Put water and the raw materials of the water reducing agent into the stirrer and start stirring; Sequentially add other materials, control the stirring time within 30 - 45 minutes, and control the stirring speed within 500 - 1500 revolutions per minute.

4. The preparation method of the steam-curing-free precast concrete low-carbon early-strength water-reducing agent according to claim 2, characterized in that, The said temperature control step includes ensuring that the temperature during the stirring process is maintained between 20℃ - 30℃ through the temperature control system.

5. The preparation method of the steam-curing-free precast concrete low-carbon early-strength water-reducing agent according to claim 2, characterized in that, The said pH value adjustment step includes: Adjust the pH to the range of 7.5 - 8.5 by adding acid or alkali to promote the stability of the water reducing agent and the smooth progress of the cement hydration reaction.

6. The preparation method of the steam-curing-free precast concrete low-carbon early-strength water reducer according to claim 2, wherein, The said standing and filtration step includes: Let the stirred mixed solution stand for 2 hours to ensure that the reaction proceeds fully; After standing, remove the undissolved impurities through a filter to ensure the purity of the final water reducing agent material.

7. The preparation method of the steam-curing-free precast concrete low-carbon early-strength water reducing agent according to claim 2, characterized in that, The said storage and packaging step includes: Put the finally prepared water reducing agent into a standard sealed container, ensure that the container material is suitable for long-term storage, prevent contact with moisture or pollutants in the air, and avoid deterioration of the water reducing agent; The storage environment should be controlled within the temperature range of 20℃ - 30℃, and keep the relative humidity below 50%. At the same time, ensure good ventilation in the storage space to avoid the influence of high temperature, high humidity and direct sunlight on the water reducing agent.

8. The preparation method of the steam-curing-free precast concrete low-carbon early-strength water-reducing agent according to claim 7, characterized in that, The said storage and packaging step further includes: Use a polyethylene film before packaging to prevent the water reducing agent from reacting with moisture in the air and causing changes in its properties, thus affecting the use effect. During the packaging process, use a sealed container that meets food-grade or chemical packaging standards to prevent moisture and impurities in the air from entering and ensure the purity of the product; When closing the container, ensure that the seal is tight to avoid leakage or air entry during transportation and storage.

9. Application of a precast concrete low-carbon early strength water reducing agent without steam curing, characterized in that, Use the steam-curing-free precast concrete low-carbon early-strength water reducer described in claim 1, and apply the water reducer to precast concrete, which is particularly suitable for the production of precast concrete under conditions without steam curing.

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