Super-early-strength crystal nucleus concrete and preparation method thereof
By adding nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to concrete, the problem of high cost of high-temperature steam curing is solved, and early strength and production efficiency are improved, especially in maintaining strength during freezing cycles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DAWNING PREFABRICATED BUILDING TECH (ZHEJIANG) CO LTD
- Filing Date
- 2026-02-07
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies are costly in improving the early strength of precast concrete, and high-temperature steam curing methods are inefficient and difficult to quickly turn over molds with limited equipment and space.
Nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are used as additives. They are mixed to form mixed particles, which are then spray-dried and mixed with cement, fly ash, sand, stone and other materials to improve the early strength of concrete.
It effectively improves the 1-day compressive strength of concrete, reduces slump, enhances frost resistance, and increases production efficiency.
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Abstract
Description
Technical Field
[0001] This invention relates to an ultra-early strength nucleated concrete and its preparation method. Background Technology
[0002] Concrete, as a fundamental material in modern engineering construction, plays an irreplaceable role in projects such as water conservancy projects, transportation infrastructure, and super high-rise buildings. According to the latest statistics from the International Concrete Institute (FIB), the global annual consumption of concrete has exceeded 30 billion tons, of which hydraulic concrete accounts for 12% to 15%, and its scale effect significantly influences the quality of major national infrastructure construction.
[0003] With the rapid development of prefabricated buildings in my country, the demand for precast concrete components is constantly increasing. In the production process of precast components, in order to improve production efficiency under limited equipment and space conditions, enterprises often accelerate production speed by increasing the early strength of precast concrete, thereby speeding up mold turnover. A commonly used method to improve the early strength of precast concrete is high-temperature steam curing, which promotes early strength and accelerates mold turnover. However, due to the high cost of high-temperature steam curing, developing a method to improve the early strength of precast concrete is of great significance. Summary of the Invention
[0004] One of the objectives of this invention is to provide an ultra-early strength nucleated concrete, which has the advantage of improving the early strength of precast concrete.
[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: An ultra-early strength nucleated concrete includes a nano-SiO2 nucleated early strength agent and hydroxypropyl methylcellulose; the ratio of the nano-SiO2 nucleated early strength agent to hydroxypropyl methylcellulose by mass is 1:2~5.
[0006] Furthermore, the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and spray drying is performed to form mixed particles.
[0007] Furthermore, it includes cement, fly ash, sand, stone, water, nano-SiO2 crystal nucleation early strength agent and hydroxypropyl methylcellulose; The mass fractions of cement, fly ash, sand, stone, and water are 100 parts, 24-26 parts, 290-320 parts, 340-380 parts, and 55-60 parts, respectively. The doping amount of the nano-SiO2 nucleation early strength agent is 1~5wt%; The ratio of the nano-SiO2 nucleation early strength agent to hydroxypropyl methylcellulose is 1:2~5.
[0008] Furthermore, it includes cement, fly ash, sand, stone, water, nano-SiO2 crystal nucleation early strength agent and hydroxypropyl methylcellulose; The mass fractions of cement, fly ash, sand, stone, and water are 100 parts, 25 parts, 300 parts, 360 parts, and 56 parts, respectively. The doping amount of the nano-SiO2 nucleation early strength agent is 1~2wt%; The ratio of the nano-SiO2 nucleation early strength agent to hydroxypropyl methylcellulose is 1:3.
[0009] Furthermore, it also includes polypropylene fibers, wherein the doping amount of the polypropylene fibers is 0.08~0.12wt%.
[0010] Furthermore, it also includes polyvinyl alcohol fibers, wherein the doping amount of the polyvinyl alcohol fibers is 0.03~0.06wt%.
[0011] The second objective of this invention is to provide a method for preparing ultra-early strength nucleated concrete.
[0012] A method for preparing an ultra-early strength crystalline nucleus concrete is characterized by the following steps: weighing each raw material according to the proportion, mixing cement, fly ash, sand, stone and water in proportion and stirring evenly, and then adding other raw materials and mixing evenly.
[0013] Further steps include: weighing each raw material according to the proportion, mixing cement, fly ash, sand, stone and water in proportion and stirring evenly, and then adding SiO2 crystal nucleation early strength agent and hydroxypropyl methylcellulose and mixing evenly. The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and then spray-dried to form mixed particles.
[0014] Further steps include: weighing each raw material according to the proportion, mixing cement, fly ash, sand, stone and water in proportion and stirring evenly, and then adding SiO2 crystal nucleation early strength agent, hydroxypropyl methylcellulose, polypropylene fiber and polyvinyl alcohol fiber and mixing evenly. The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and then spray-dried to form mixed particles.
[0015] The main technical effects of this invention are reflected in the following aspects: Concrete with added nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose can effectively improve the 1-day compressive strength of cement and has the advantage of improving the early strength of precast concrete. As the doping amount of nano-SiO2 nucleation early strength agent increases, the slump decreases. In particular, when the doping amount is greater than 5%, the slump drops rapidly. When no hydroxypropyl methylcellulose is added to the system, the slump is more obvious.
[0016] By keeping the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose unchanged, the sequential addition of polypropylene fiber and polyvinyl alcohol fiber can improve the strength retention rate of concrete during freezing cycles and enhance its freeze-thaw resistance. Detailed Implementation
[0017] Unless otherwise specified, the cement used in this application is 42.5 ordinary Portland cement, the fly ash is Class II fly ash from power plants, the sand is river sand, medium sand with a fineness modulus of 2.4, and the stone is crushed stone with a particle size of 5~25mm.
[0018] Example 1: An ultra-early strength crystalline nucleus concrete, prepared by the following method: The raw materials are weighed according to the specified proportions. 100 parts by weight of cement, 25 parts by weight of fly ash, 300 parts by weight of sand, 360 parts by weight of aggregate, and 56 parts by weight of water are mixed and stirred evenly. Then, nano-SiO2 crystalline nucleus early strength agent and hydroxypropyl methylcellulose are added and mixed evenly. The doping amount of the nano-SiO2 crystalline nucleus early strength agent is 1~5 wt%; the ratio of nano-SiO2 crystalline nucleus early strength agent to hydroxypropyl methylcellulose is 1:2~5.
[0019] The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and spray drying is performed to form mixed particles.
[0020] Example 2: An ultra-early-strength nucleated concrete, prepared by the following method: Raw materials are weighed according to the specified proportions. 100 parts by weight of cement, 25 parts by weight of fly ash, 300 parts by weight of sand, 360 parts by weight of aggregate, and 56 parts by weight of water are mixed and stirred evenly. Then, nano-SiO2 nucleated early-strength agent, hydroxypropyl methylcellulose, and polypropylene fiber are added and mixed evenly. The doping amount of nano-SiO2 nucleated early-strength agent is 1-2 wt%; the ratio of nano-SiO2 nucleated early-strength agent to hydroxypropyl methylcellulose is 1:3. The doping amount of polypropylene fiber is 0.08-0.12 wt%.
[0021] The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and spray drying is performed to form mixed particles.
[0022] Example 3: An ultra-early-strength crystalline nucleus concrete, prepared by the following method: Raw materials are weighed according to the specified proportions. 100 parts by weight of cement, 25 parts by weight of fly ash, 300 parts by weight of sand, 360 parts by weight of aggregate, and 56 parts by weight of water are mixed and stirred evenly. Then, nano-SiO2 crystalline nucleus early-strength agent, hydroxypropyl methylcellulose, polypropylene fiber, and polyvinyl alcohol fiber are added and mixed evenly. The doping amount of nano-SiO2 crystalline nucleus early-strength agent is 1-2 wt%; the ratio of nano-SiO2 crystalline nucleus early-strength agent to hydroxypropyl methylcellulose is 1:3. The doping amount of polypropylene fiber is 0.08-0.12 wt%. The doping amount of polyvinyl alcohol fiber is 0.03-0.06 wt%.
[0023] The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and spray drying is performed to form mixed particles.
[0024] Performance testing 1. Concrete slump, slump loss over time and setting time: Tested according to GB / T50080—2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures".
[0025] The test subject is an ultra-early strength crystal nucleus concrete, which is prepared by the following method: weigh each raw material according to the proportion, mix 100 parts by weight of cement, 25 parts by weight of fly ash, 300 parts by weight of sand, 360 parts by weight of stone, and 56 parts by weight of water in proportion and stir evenly, then add other SiO2 crystal nucleus early strength agent and hydroxypropyl methylcellulose and mix evenly.
[0026] The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and spray drying is performed to form mixed particles.
[0027] The doping amount of the nano-SiO2 nucleation early strength agent is 0~6wt%; the ratio of the nano-SiO2 nucleation early strength agent to hydroxypropyl methylcellulose is 1:3.
[0028] Table 1
[0029] As shown in Table 1, the slump decreases with increasing doping concentration of the nano-SiO2 nucleation early strength agent, especially when the doping concentration exceeds 5%, the slump drops rapidly. The slump decrease is even more pronounced when hydroxypropyl methylcellulose is not added to the system.
[0030] 2. Freeze resistance test Concrete performance testing was conducted according to the "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete" (GB / T50082-2024), primarily testing the compressive strength retention rate. Freeze-thaw resistance was assessed using the rapid freeze-thaw method, with a freeze-thaw temperature range of -17℃ to +8℃. Each cycle lasted 2 to 4 hours, with three stages of 25, 50, and 75 cycles, during which the decrease in compressive strength was recorded. Compressive strength testing was performed according to standard methods using 100mm cube specimens. Curing methods included standard curing (20±2℃, humidity >95%) and air curing (20±5℃, ventilated environment).
[0031] The test subject is an ultra-early strength crystal nucleus concrete, which is prepared by the following method: weigh each raw material according to the proportion, mix 100 parts by weight of cement, 25 parts by weight of fly ash, 300 parts by weight of sand, 360 parts by weight of stone, and 56 parts by weight of water in a proportion and stir evenly, then add other SiO2 crystal nucleus early strength agent, hydroxypropyl methylcellulose, polypropylene fiber, and polyvinyl alcohol fiber and mix evenly.
[0032] The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and spray drying is performed to form mixed particles.
[0033] The doping amount of the nano-SiO2 nucleation early strength agent is 1~5wt%; the ratio of the nano-SiO2 nucleation early strength agent to hydroxypropyl methylcellulose is 1:3.
[0034] Polypropylene fibers and polyvinyl alcohol fibers are uniformly mixed. The doping amount of nano-SiO2 nucleation early strength agent is 1~2wt%; the ratio of nano-SiO2 nucleation early strength agent to hydroxypropyl methylcellulose is 1:3. The doping amount of polypropylene fibers is 0.08~0.12wt%. The doping amount of polyvinyl alcohol fibers is 0.03~0.06wt%.
[0035] Table 2
[0036] As shown in Table 2, the strength retention rate of the three groups of concrete decreased with the increase of the number of cycles; after 75 cycles, sample 3 was still able to maintain 94.2, sample 2 dropped to 86.6%, and sample 1C was the lowest at 74.1, with sample 1C decreasing the most rapidly and having relatively weak frost resistance.
[0037] Of course, the above are just typical examples of the present invention. In addition, the present invention may have many other specific embodiments. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.
Claims
1. A type of ultra-early-strength nucleated concrete, characterized in that, It includes a nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose; the ratio of the nano-SiO2 nucleation early strength agent to hydroxypropyl methylcellulose by mass is 1:2~5.
2. The ultra-early strength nucleated concrete according to claim 1, characterized in that, The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and then spray-dried to form mixed particles.
3. The ultra-early strength nucleated concrete according to claim 2, characterized in that, Including cement, fly ash, sand, stone, water, nano-SiO2 crystal nucleation early strength agent, and hydroxypropyl methylcellulose; The mass fractions of cement, fly ash, sand, stone, and water are 100 parts, 24-26 parts, 290-320 parts, 340-380 parts, and 55-60 parts, respectively. The doping amount of the nano-SiO2 nucleation early strength agent is 1~5wt%; The ratio of the nano-SiO2 nucleation early strength agent to hydroxypropyl methylcellulose is 1:2~5.
4. The ultra-early strength nucleated concrete according to claim 3, characterized in that, Including cement, fly ash, sand, stone, water, nano-SiO2 crystal nucleation early strength agent, and hydroxypropyl methylcellulose; The mass fractions of cement, fly ash, sand, stone, and water are 100 parts, 25 parts, 300 parts, 360 parts, and 56 parts, respectively. The doping amount of the nano-SiO2 nucleation early strength agent is 1~2wt%; The ratio of the nano-SiO2 nucleation early strength agent to hydroxypropyl methylcellulose is 1:
3.
5. The ultra-early strength nucleated concrete according to claim 4, characterized in that, It also includes polypropylene fibers, wherein the doping amount of the polypropylene fibers is 0.08~0.12wt%.
6. The ultra-early strength nucleated concrete according to claim 5, characterized in that, It also includes polyvinyl alcohol fibers, wherein the doping amount of the polyvinyl alcohol fibers is 0.03~0.06wt%.
7. A method for preparing an ultra-early strength nucleated concrete as described in any one of claims 1-6, characterized in that, Includes the following steps: Weigh each raw material according to the proportion, mix cement, fly ash, sand, stone and water in the proportion and stir evenly, then add other raw materials and mix evenly.
8. The method for preparing ultra-early strength nucleated concrete according to claim 7, characterized in that, Includes the following steps: Weigh each raw material according to the proportion, mix cement, fly ash, sand, stone and water in proportion and stir evenly, then add rice SiO2 crystal nucleation early strength agent and hydroxypropyl methylcellulose and mix evenly. The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and then spray-dried to form mixed particles.
9. The method for preparing ultra-early strength nucleated concrete according to claim 8, characterized in that, Includes the following steps: Weigh each raw material according to the proportion, mix cement, fly ash, sand, stone and water evenly, then add SiO2 crystal nucleation early strength agent, hydroxypropyl methylcellulose, polypropylene fiber and polyvinyl alcohol fiber and mix evenly. The nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose are added in the form of mixed particles: water is added to the nano-SiO2 nucleation early strength agent and hydroxypropyl methylcellulose to form a mixed solution, and then spray-dried to form mixed particles.