Mechanism sand foam concrete and preparation method thereof
By combining modified protein foaming agents and lightweight materials, the stability and strength problems of foamed concrete are solved, and the shrinkage resistance and waterproof performance of manufactured sand foamed concrete are improved, making it suitable for widespread application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CSCEC WESTERN CONSTR XINJIANG CO LTD
- Filing Date
- 2024-01-25
- Publication Date
- 2026-07-03
AI Technical Summary
Traditional foamed concrete has a low consistency, which cannot effectively overcome the expansion force of the foam surface. The foam diameter in the slurry is uneven, resulting in poor stability and problems such as low strength, large shrinkage, easy cracking, and easy water absorption. This is especially evident when using manufactured sand with a large fineness modulus and poor gradation.
By using modified protein foaming agents combined with components such as manufactured sand, expanded perlite, and graphene oxide, a stable foam system is formed by improving the surface tension and particle size distribution of the foam, and lightweight materials are used to enhance the shrinkage resistance and waterproof performance of concrete.
This method improves the stability and mechanical properties of foamed concrete, reduces its density, and provides good shrinkage resistance and waterproofing, making it suitable for widespread application.
Smart Images
Figure BDA0004681150620000061
Abstract
Description
Technical Field
[0001] This invention belongs to the field of building materials technology, specifically relating to a manufactured sand foamed concrete and its preparation method. Background Technology
[0002] Foamed concrete has low density and excellent functions such as heat insulation, sound insulation, and moisture resistance. It is suitable for use as a heat insulation material for walls. Moreover, it requires less investment in production, is easy to construct, and can make extensive use of industrial waste. It is of great significance for building energy conservation and environmental protection.
[0003] Foamed concrete is typically produced by mechanically preparing a foaming agent solution into foam. Cement, sand, and other materials are mixed into mortar at a concrete mixing plant and transported to the construction site using a truck-mounted mixer. The separately prepared foam is then added to the mortar and mixed thoroughly. Finally, the prepared foamed concrete is injected into a pump truck for delivery or directly applied on-site.
[0004] However, traditional foamed concrete typically has a low consistency, which is insufficient to overcome the surface expansion force of the foam. This results in inconsistent foam diameters at different locations within the slurry, leading to unstable foaming, reduced foaming rate, and ultimately affecting the quality of the foam. Furthermore, traditional foamed concrete slurry suffers from poor stability, exhibiting low strength, high shrinkage, susceptibility to cracking, and high water absorption, severely hindering its large-scale application in the construction industry. Moreover, the use of manufactured sand with high fineness modulus and poor gradation further exacerbates the stability issues of foamed concrete. Summary of the Invention
[0005] The main objective of this invention is to address the problems and shortcomings of existing technologies by providing a manufactured sand foamed concrete that, while ensuring good mechanical properties, also achieves good shrinkage resistance and waterproofing performance, and effectively reduces density. This enables the effective application of manufactured sand with a fineness modulus in foamed concrete. Furthermore, the preparation method involved is relatively simple and easy to operate, making it suitable for widespread application.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] A type of manufactured sand foamed concrete, comprising the following components and their respective weight percentages: 150-400 parts silicate cement, 50-150 parts fly ash, 30-70 parts silica fume, 120-650 parts manufactured sand, 60-110 parts expanded perlite, 10-30 parts graphene oxide dispersion, 5-10 parts steel fiber, 5-10 parts water-reducing agent, 2.5-10 parts modified protein foaming agent, and 220-250 parts water.
[0008] In the above scheme, the 28-day compressive strength of the silicate cement mortar is 59.8–61.8 MPa, and the specific surface area is 380–450 m². 2 / kg, apparent density 3060~3080kg / m³ 3 Specifically, P·I type 52.5 cement or P·II type 52.5 cement can be selected.
[0009] In the above scheme, the fly ash is Class F, Grade II, with a 28-day mortar activity of 68-75%, a fineness of 21.2-27.5%, and an apparent density of 2360-2390 kg / m³. 3 .
[0010] In the above scheme, the silica fume has a silica content of 92-95% and a specific surface area of 26,000-28,000 m². 2 / kg, with an activity of 110-116% after 28 days.
[0011] In the above scheme, the manufactured sand has a stone powder content of 10.5–11.2 wt%, is a medium-grade sand at the lower limit of Zone II, and has an apparent density of 2660–2690 kg / m³. 3 The fineness modulus is 2.6 to 2.9, and the needle-like and flaky particles account for 2% to 5%.
[0012] In the above scheme, the expanded perlite expands 10 to 15 times in volume and has a bulk density of 515 to 782 kg / m³. 3 .
[0013] In the above scheme, the concentration of the graphene oxide dispersion is 3.8 to 4.5 mg / mL.
[0014] In the above scheme, the length of the steel fiber is 45-60mm and the diameter is 0.45-0.5mm.
[0015] In the above scheme, the water-reducing agent has a water reduction rate of 25-26% and a solid content of 11.5-12.9%.
[0016] In the above scheme, the main raw materials and their weight percentages in the modified protein foaming agent include: 20-30 parts animal keratin, 2.5-6.5 parts Ca(OH)2, 0.5-2.5 parts NaHSO3, 200-250 parts water, 0.2-0.5 parts gum arabic powder, and 0.05-0.10 parts triethanolamine. The specific preparation steps include: placing the weighed animal keratin, Ca(OH)2, and NaHSO3 in boiling water for hydrolysis (5-7 hours), cooling to room temperature (20-25°C), filtering the residue, adjusting the pH of the filtrate to 7.0-8.5 with a weak acid (such as anhydrous acetic acid), adding gum arabic powder to the resulting mixture for a first stirring treatment, and finally adding triethanolamine dropwise for a second stirring treatment to obtain the modified protein foaming agent.
[0017] In the above scheme, the animal horn can be selected from cow horn, horse horn, pig horn, etc.
[0018] In the above scheme, the boiling water temperature is 98-100℃.
[0019] In the above scheme, the temperature for the first stirring treatment is 20-25℃, the rotation speed is 120-130 r / min, and the time is 10-15 min; the temperature for the second stirring treatment is 20-25℃, the rotation speed is 120-130 r / min, and the time is 25-30 min.
[0020] In the above scheme, the density of the gum arabic powder is 1.35–1.49 g / cm³. 3 It is a white powder, odorless, tasteless, and easily soluble in water.
[0021] In the above scheme, the density of the foam obtained using the modified protein foaming agent is 830-1080 kg / m³. 3 The foam stability is 2-4 hours.
[0022] The above-mentioned method for preparing manufactured sand foamed concrete includes the following steps:
[0023] 1) Mix the modified protein foaming agent with a portion of water and mechanically foam to obtain foam;
[0024] 2) Weigh out the silicate cement, fly ash, silica fume, manufactured sand, expanded perlite, graphene oxide, and steel fiber and mix them (30-45s). Then add the water-reducing agent and the remaining amount of water and mix them (50-120s). Finally, add the foam and mix evenly (15-30s) to obtain the manufactured sand foam concrete mixture.
[0025] 3) The resulting mixture is poured into shape, left to cure statically, and then subjected to standard curing to obtain machine-made sand foam concrete.
[0026] In the above scheme, the foaming step includes: under the rotation and stirring of the perforated blades in the foam generator, the modified protein foaming agent aqueous solution gradually produces abundant white foam. The speed of the foam generator is 7 to 10 revolutions per minute, and the foaming time is 3 to 4 minutes. When the foam quantity is close to the maximum, the foam can be taken out in a container after standing for 1 to 2 minutes.
[0027] In the above scheme, the mass ratio of modified protein foaming agent to water in step 1) is 1:(10-30).
[0028] In the above scheme, the pouring and molding process does not require intermediate processes such as ground mixing and vibration compaction, and the foamed concrete slurry should be higher than the upper edge of the mold during molding.
[0029] In the above scheme, the static curing time is 24 to 48 hours, and the surface cannot be smoothed or flattened. The temperature is 20 to 24°C.
[0030] In the above plan, the standard curing temperature is 20-22℃ and the humidity is 96-99%.
[0031] The manufactured sand foamed concrete prepared according to the above scheme has a shrinkage rate of 235–395 × 10⁻⁶. -6 The compressive strength can reach up to 18 MPa, and the density can be as low as 850 kg / m³. 3 The water absorption rate is 1.0-1.6%. While ensuring good mechanical properties, it can also take into account good anti-shrinkage and waterproof properties, and can effectively reduce the density, making it suitable for widespread application.
[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0033] 1) This invention uses triethanolamine and gum arabic powder to modify protein-type foaming agents. By introducing and then draining the protein system after hydrolysis, triethanolamine is first added for one stirring modification to reduce the surface tension of the foam and improve the elasticity of individual foams. Then gum arabic powder is introduced to increase the viscosity of the liquid phase and slow down the drainage rate of the foam. Finally, the pH value is adjusted to obtain a stable foam system with a large amount of foam and a relatively uniform particle size distribution, thereby promoting the stability of the obtained foamed concrete slurry.
[0034] 2) The manufactured sand and expanded perlite used in this invention have high porosity, and the manufactured sand has a large fineness modulus and poor gradation. In addition, the filling effect of graphene oxide, silica fume and other materials is combined to form a reasonable bulk density of foam concrete paste aggregate, which can promote the improvement of the early spatial support performance of foam concrete, which is conducive to ensuring good concrete stability, internal water retention, and later strength stability, and has excellent crack resistance. Moreover, all of them are lightweight raw materials with low overall density and good moisture-proof and heat insulation effects.
[0035] 3) The preparation method involved in this invention is relatively simple and easy to operate, and can realize the effective application of manufactured sand with large fineness modulus and poor gradation in foamed concrete; the resulting manufactured sand foamed concrete can take into account good shrinkage resistance, waterproof performance and lightweight performance while ensuring good mechanical properties, and is suitable for promotion and application. Detailed Implementation
[0036] This invention is not limited to the embodiments described above. Those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention. Contents not described in detail in this specification are prior art known to those skilled in the art.
[0037] In the following embodiments, the silicate cement used is P·I type 52.5 cement, which has a 28-day mortar compressive strength of 60.8 MPa and a specific surface area of 420 m². 2 / kg, apparent density 3080kg / m³ 3 The fly ash is classified as Class F, Grade II, with a 28-day mortar activity of 72%, a fineness of 25.3%, and an apparent density of 2375 kg / m³. 3 The silica ash has a silica content of 92% and a specific surface area of 26,000 m². 2 / kg, with a 28-day activity of 116%. The manufactured sand is siliceous manufactured sand with a stone powder content of 10.8wt%, classified as a medium-grade sand at the lower limit of Zone II, and an apparent density of 2680 kg / m³. 3 Expanded perlite expands 12 times in volume, with a bulk density of 565 kg / m³. 3 The concentration of the graphene oxide dispersion was 4.2 mg / mL. The steel fiber filaments had a length of 45–60 mm and a diameter of 0.45–0.5 mm.
[0038] The polycarboxylate high-performance water-reducing agent used has a water reduction rate of 26% and a solid content of 12.6%.
[0039] Example 1
[0040] A type of manufactured sand foamed concrete comprises the following components and their respective weight percentages: 350 parts silicate cement, 100 parts fly ash, 50 parts silica fume, 624 parts manufactured sand, 70 parts expanded perlite, 15 parts graphene oxide dispersion, 6 parts steel fiber, 7 parts water-reducing agent, 3.5 parts modified protein foaming agent, and 230 parts water; its preparation method includes the following steps:
[0041] 1) Mix the foaming agent with 30% water (69 parts), with a mass ratio of foaming agent to water of 1:20. In a foam generator, the foaming agent solution gradually produces abundant white foam through rotational stirring with perforated blades. The foam generator speed is 10 r / min, foaming time is 4 minutes, and after standing for 2 minutes, the foam can be removed into a container. The resulting foam volume is 825 mL, and the density is 952 kg / m³. 3 The foam stability is 2.4 hours.
[0042] The preparation steps of the modified protein foaming agent are as follows: 30 parts of bovine hoof horn, 5.5 parts of Ca(OH)2, and 2.3 parts of NaHSO3 are placed in 210 parts of water (100℃) for hydrolysis for 6.5 hours. The mixture is then cooled to room temperature (22℃), and the residue is filtered. The pH of the filtrate is adjusted to 7.5 with a weak acid (anhydrous acetic acid). 0.1 parts of triethanolamine are then added, and the mixture is stirred for 15 minutes at a controlled temperature of 22℃ and a stirring speed of 120 r / min. Finally, 0.3 parts of gum arabic powder (density 1.35 g / cm³) are added. 3 Continue stirring at the same speed for 30 minutes to obtain the modified protein foaming agent;
[0043] 2) Weigh out silicate cement, fly ash, silica fume, manufactured sand, expanded perlite, graphene oxide, and steel fiber and stir for 30 seconds. Then add water-reducing agent and the remaining water and mix for 50 seconds. Finally add foam and stir for 15 seconds to obtain the manufactured sand foam concrete mixture.
[0044] 3) The obtained mixture is poured into a mold without the need for mixing and compaction. The foamed concrete slurry should be higher than the upper edge of the mold during molding. It should be left to cure for 24 hours without smoothing or finishing. The temperature should be 22℃. Then it should be cured at 21℃ and 99% humidity to obtain the machine-made sand foamed concrete.
[0045] Example 2
[0046] A type of manufactured sand foamed concrete comprises the following components and their respective weight percentages: 330 parts silicate cement, 110 parts fly ash, 30 parts silica fume, 550 parts manufactured sand, 70 parts expanded perlite, 15 parts graphene oxide dispersion, 7 parts steel fiber, 7.5 parts water-reducing agent, 4 parts modified protein foaming agent, and 220 parts water; its preparation method includes the following steps:
[0047] 1) Mix the modified protein foaming agent (preparation method is the same as in Example 1) with 50% of the amount of water (110 parts). The mass ratio of foaming agent to water is 1:27.5. Under the rotation and stirring of the foaming agent aqueous solution in the foam generator with perforated blades, rich white foam is gradually produced. The speed of the foam generator is 10 revolutions / minute. After foaming for 4 minutes and standing for 2 minutes, the foam can be taken out with a container.
[0048] 2) Weigh out silicate cement, fly ash, silica fume, manufactured sand, expanded perlite, graphene oxide, and steel fiber and stir for 30 seconds. Then add water-reducing agent and the remaining water and mix for 60 seconds. Finally, add foam and stir for 30 seconds to obtain a manufactured sand foam concrete.
[0049] 3) The obtained mixture is poured into a mold without the need for mixing and compaction. The foamed concrete slurry should be higher than the upper edge of the mold during molding. It should be left to cure for 48 hours without smoothing or finishing. The temperature should be 22℃. Then it should be cured at 21℃ and 99% humidity to obtain the machine-made sand foamed concrete.
[0050] Example 3
[0051] A type of manufactured sand foamed concrete comprises the following components and their respective weight percentages: 300 parts silicate cement, 75 parts fly ash, 55 parts silica fume, 610 parts manufactured sand, 80 parts expanded perlite, 20 parts graphene oxide dispersion, 9 parts steel fiber, 8 parts water-reducing agent, 8 parts modified protein foaming agent, and 250 parts water; its preparation method includes the following steps:
[0052] 1) Mix the modified protein foaming agent (preparation method is the same as in Example 1) with 50% of the amount of water (125 parts). The mass ratio of foaming agent to water is 1:16. Under the rotation and stirring of the foaming agent aqueous solution in the foam generator with perforated blades, rich white foam is gradually produced. The speed of the foam generator is 10 revolutions / minute. After foaming for 4 minutes and standing for 2 minutes, the foam can be taken out with a container.
[0053] 2) Weigh out silicate cement, fly ash, silica fume, manufactured sand, expanded perlite, graphene oxide, and steel fiber and stir for 30 seconds. Then add water-reducing agent and the remaining water and mix for 60 seconds. Finally, add foam and stir for 30 seconds to obtain the manufactured sand foam concrete mixture.
[0054] 3) The obtained mixture is poured into a mold without the need for mixing and compaction. The foamed concrete slurry should be higher than the upper edge of the mold during molding. It should be left to cure for 36 hours without smoothing or finishing. The temperature should be 22℃. Then it should be cured at 21℃ and 99% humidity to obtain machine-made sand foamed concrete.
[0055] Comparative Example 1
[0056] A type of manufactured sand foamed concrete is prepared in a manner largely similar to that of Example 1, except that the modified foaming agent is prepared as follows: 30 parts of cow hoof horn, 5.5 parts of Ca(OH)2, and 2.3 parts of NaHSO3 are placed in 210 parts of water (100°C) for hydrolysis for 6.5 hours. After hydrolysis, the mixture is cooled to room temperature (22°C), and the residue is filtered. The pH of the filtrate is adjusted to 7.5 with a weak acid (anhydrous acetic acid). 0.4 parts of triethanolamine are added to the resulting mixture and stirred for 30 minutes at a controlled temperature of 22°C and a stirring speed of 120 r / min to obtain the protein foaming agent.
[0057] Comparative Example 2
[0058] A type of manufactured sand foamed concrete is prepared using a method largely the same as in Example 1, except that the modified foaming agent is prepared as follows: 30 parts of cow hoof horn, 5.5 parts of Ca(OH)2, and 2.3 parts of NaHSO3 are placed in 210 parts of water (100℃) for hydrolysis for 6.5 hours. After hydrolysis, the mixture is cooled to room temperature (22℃), and the residue is filtered. The pH of the filtrate is adjusted to 7.5 with a weak acid (anhydrous acetic acid), and 0.4 parts of gum arabic powder (density 1.35 g / cm³) are added. 3 The mixture was stirred for 30 minutes at a controlled temperature of 22°C and a rotation speed of 120 r / min to obtain a protein foaming agent.
[0059] Comparative Example 3
[0060] A type of manufactured sand foamed concrete is prepared using a method largely similar to that of Example 1, except that the modified foaming agent is prepared as follows: 30 parts of cow hoof horn, 5.5 parts of Ca(OH)2, and 2.3 parts of NaHSO3 are placed in 210 parts of water (100°C) for hydrolysis for 6.5 hours. After hydrolysis, the mixture is cooled to room temperature (22°C), and the residue is filtered. The pH of the filtrate is adjusted to 7.5 with a weak acid (anhydrous acetic acid), and 0.3 parts of gum arabic powder (density 1.35 g / cm³) are added simultaneously. 3 The protein foaming agent was prepared by stirring 0.1 parts of triethanolamine with 0.1 parts of triethanolamine for 30 minutes, controlling the temperature at 22℃ and the rotation speed at 120 r / min.
[0061] The manufactured sand foamed concrete described in Examples 1-3 and Comparative Examples 1-3 were tested for foam stability, mechanical properties, water absorption and shrinkage properties, and the results are shown in Table 1.
[0062] Table 1. Performance test results of the manufactured sand foamed concrete obtained in Examples 1-3 and Comparative Examples 1-3.
[0063]
[0064] Obviously, the above preferred embodiments are merely examples for clear illustration and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A type of manufactured sand foamed concrete, characterized in that, The components and their respective weight percentages are as follows: 150-400 parts silicate cement, 50-150 parts fly ash, 30-70 parts silica fume, 120-650 parts manufactured sand, 60-110 parts expanded perlite, 10-30 parts graphene oxide dispersion, 5-10 parts steel fiber, 5-10 parts water-reducing agent, 2.5-10 parts modified protein foaming agent, and 220-250 parts water; The preparation steps of the modified protein foaming agent include: placing weighed animal keratin, Ca(OH)2 and NaHSO3 in boiling water for hydrolysis, cooling to room temperature, filtering the residue, adjusting the pH of the obtained filtrate to 6.5~7.0 with a weak acid, adding triethanolamine to the obtained mixture for a first stirring treatment, and finally adding gum arabic powder for a second stirring treatment to obtain the modified protein foaming agent; The manufactured sand has a stone powder content of 10.5~11.2wt%, is a medium-grade sand at the lower limit of Zone II, and has an apparent density of 2660~2690 kg / m³. 3 The fineness modulus is 2.6~2.9, and the needle-like and flaky particles account for 2~5%; The steel fiber filaments are 45-60 mm in length and 0.45-0.5 mm in diameter.
2. The manufactured sand foamed concrete according to claim 1, characterized in that, The modified protein foaming agent comprises the following main raw materials and their weight percentages: 20-30 parts animal keratin, 2.5-6.5 parts Ca(OH)2, 0.5-2.5 parts NaHSO3, 200-250 parts water, 0.2-0.5 parts gum arabic powder, and 0.05-0.10 parts triethanolamine.
3. The manufactured sand foamed concrete according to claim 1, characterized in that, The 28-day compressive strength of the silicate cement mortar is 59.8~61.8 MPa, and the specific surface area is 380~450 m². 2 / kg, apparent density 3060~3080 kg / m³ 3 The fly ash is classified as Class F, Grade II, with a 28-day mortar activity of 68-75%, a fineness of 21.2-27.5%, and an apparent density of 2360-2390 kg / m³. 3 The silica content in silica fume is 92-95%, and the specific surface area is 26,000-28,000 m². 2 / kg, with an activity of 110~116% after 28 days.
4. The manufactured sand foamed concrete according to claim 1, characterized in that, The expanded perlite expands 10 to 15 times in volume and has a bulk density of 515 to 782 kg / m³. 3 .
5. The manufactured sand foamed concrete according to claim 1, characterized in that, The concentration of the graphene oxide dispersion is 3.8~4.5 mg / mL.
6. The manufactured sand foamed concrete according to claim 1, characterized in that, The water reduction rate of the water-reducing agent is 25-26%.
7. The method for preparing manufactured sand foamed concrete according to any one of claims 1 to 6, characterized in that, Includes the following steps: 1) Mix the modified protein foaming agent with a portion of water and mechanically foam to obtain foam; 2) Weigh out the silicate cement, fly ash, silica fume, manufactured sand, expanded perlite, graphene oxide dispersion, and steel fiber and mix them. Then add the water-reducing agent and the remaining amount of water and mix them. Finally, add the foam and mix evenly to obtain the manufactured sand foam concrete mixture. 3) The obtained manufactured sand foamed concrete mixture is poured into shape, left to cure statically, and then subjected to standard curing to obtain manufactured sand foamed concrete.