Desert-sand foam concrete and method for producing the same
Patent Information
- Application Number
- CN202611107611.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-24
- Publication Date
- 2026-09-15
AI Technical Summary
[0006]本发明的目的在于解决现有泡沫混凝土强度低、吸水率高、性能不稳定的问题，同时实现沙漠沙和工业固废的资源化利用，并有效平衡材料的轻质、保温与力学性能，提供一种沙漠沙泡沫混凝土及其制备方法
1.性能协同优化，实现强度与保温的平衡。本发明通过科学配比，利用沙漠沙的微集料填充效应、再生微粉和粉煤灰的火山灰效应，三者协同作用，优化了基体的孔结构和凝胶产物分布。这不仅提高了泡沫混凝土的密实度，还增强了孔壁强度。测试结果表明，本发明产品在保持低干密度（272~401 kg/m3）和低导热系数（0.022~0.074 W/m·K）的同时，抗压强度可达0.83~1.43 MPa，综合性能显著优于传统泡沫混凝土。
Smart Images
Figure CN122749040A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials technology, and in particular to a desert sand foam concrete and its preparation method. Background Technology
[0002] With the accelerated pace of infrastructure construction, the demand for concrete has increased dramatically, leading to the over-exploitation and depletion of river sand resources. This has resulted in serious ecological and environmental problems such as riverbed damage and embankment collapse. Therefore, finding alternatives to river sand has become an urgent need for the sustainable development of the industry.
[0003] Studies have shown that desert sand can, under certain conditions, replace or partially replace river sand in concrete preparation, and its workability, mechanical properties, and durability can meet general engineering requirements. The resource utilization of desert sand can not only alleviate the supply and demand imbalance of construction sand but also promote economic development in desert regions, possessing significant economic and social value.
[0004] On the other hand, foamed concrete has become a research hotspot in green building materials due to its advantages such as lightweight, thermal insulation, sound insulation, and high waste utilization rate. It achieves lightweight and thermal insulation by introducing uniform, closed pores into cement-based materials to form a special solid-gas interwoven structure. However, existing foamed concrete generally suffers from technical defects such as poor slurry stability, large shrinkage, easy cracking, high water absorption, and low strength, which seriously restrict its widespread application.
[0005] Therefore, how to effectively combine the abundant desert sand with foamed concrete technology, overcome the performance defects of existing foamed concrete, and at the same time realize the efficient utilization of solid waste resources, and develop a new type of green building material that is lightweight, high-strength, low water absorption and excellent thermal insulation performance, is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0006] The purpose of this invention is to solve the problems of low strength, high water absorption and unstable performance of existing foamed concrete, while realizing the resource utilization of desert sand and industrial solid waste, and effectively balancing the lightweight, heat insulation and mechanical properties of the material, so as to provide a desert sand foamed concrete and its preparation method.
[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a desert sand foamed concrete, prepared from the following raw materials: Dry materials, foaming agent, foaming water, and mixing water; The dry material comprises the following components by mass percentage: Cement 40-70%, fly ash 10-20%, recycled powder 10-20%, desert sand 10-20%; The foaming agent should be 4-6% of the dry material weight. The mass ratio of foaming agent to foaming water is 1:40~60; The water-to-binder ratio is 0.3~0.5.
[0008] As a preferred option, the foaming agent is SD-SNFP foaming agent.
[0009] As a preferred option, the fly ash is Class F, Grade I fly ash.
[0010] Preferably, the particle size of the recycled micro powder is ≤0.075mm; The particle size of desert sand is 0.015~0.02mm, and the fineness modulus is 0.3~0.35.
[0011] The present invention also provides a method for preparing the desert sand foam concrete, comprising the following steps: (1) Mix the dry materials with the mixing water to obtain a slurry; (2) Mix the foaming agent and foaming water to obtain foam; (3) Add the foam to the slurry and mix and cure in sequence to obtain the desert sand foam concrete.
[0012] Preferably, the mixing time in step (3) is ≥5 min.
[0013] Preferably, the temperature for curing in step (3) is 18~22℃ and the humidity is ≥95%.
[0014] This invention provides a desert sand foamed concrete, prepared from the following raw materials: dry materials, a foaming agent, foaming water, and mixing water; wherein the dry materials contain the following components by mass percentage: cement 40-70%, fly ash 10-20%, recycled micro powder 10-20%, and desert sand 10-20%; the foaming agent accounts for 4-6% of the dry materials' mass; the mass ratio of foaming agent to foaming water is 1:40-60; and the water-cement ratio is 0.3-0.5. This invention has the following significant beneficial effects: 1. Performance Synergistic Optimization Achieves a Balance Between Strength and Insulation. This invention utilizes a scientific ratio, leveraging the micro-aggregate filling effect of desert sand, the pozzolanic effect of recycled micro-powder and fly ash, and the synergistic effect of these three elements to optimize the pore structure and gel product distribution of the matrix. This not only improves the density of foamed concrete but also enhances the pore wall strength. Test results show that the product of this invention maintains a low dry density (272~401 kg / m³). 3 While possessing low thermal conductivity (0.022~0.074 W / m·K), it also exhibits compressive strength of 0.83~1.43 MPa, demonstrating significantly superior overall performance compared to traditional foamed concrete.
[0015] 2. Significantly reduces water absorption. By optimizing the component ratio, this invention improves the pore structure of foamed concrete, reducing interconnected pores and increasing closed pores, thereby effectively reducing water absorption.
[0016] 3. Significant resource utilization and environmental benefits. This invention utilizes desert sand extensively as natural aggregate, and incorporates recycled micro powder and industrial solid waste such as fly ash, effectively reducing dependence on and exploitation of river sand resources, promoting the recycling of industrial waste, and meeting the requirements of green building materials and sustainable development.
[0017] 4. Significant economic benefits. The cost of desert sand and industrial solid waste is far lower than that of river sand. This invention allows for the use of locally sourced materials, significantly reducing raw material costs and transportation expenses. Furthermore, its lightweight properties reduce the dead load on buildings, decreasing the cost of foundations and main structures, resulting in substantial economic benefits. Attached Figure Description
[0018] Figure 1 XRD patterns of desert sand foamed concrete in Examples 1-9; Figure 2 The images are SEM images of desert sand foam concrete from Examples 4-6. Detailed Implementation
[0019] This invention provides a desert sand foamed concrete, prepared from the following raw materials: Dry materials, foaming agent, foaming water, and mixing water; The dry material comprises the following components by mass percentage: Cement 40-70%, fly ash 10-20%, recycled powder 10-20%, desert sand 10-20%; The foaming agent should be 4-6% of the dry material weight. The mass ratio of foaming agent to foaming water is 1:40~60; The water-to-binder ratio is 0.3~0.5.
[0020] In this invention, the dry material comprises the following components by weight percentage: Cement 40-70%, fly ash 10-20%, recycled powder 10-20%, desert sand 10-20%.
[0021] In this invention, the mass percentage of cement is preferably 45-65%, more preferably 48-62%, and even more preferably 50-60%; the cement is silicate cement.
[0022] In this invention, the mass percentage of fly ash is preferably 12-18%, more preferably 14-16%, and even more preferably 14.5-15%.
[0023] In this invention, the mass percentage of the regenerated micro powder is preferably 12-18%, more preferably 14-16%, and even more preferably 14.5-15%.
[0024] In this invention, the mass percentage of desert sand is preferably 12-18%, more preferably 14-16%, and even more preferably 14.5-15%.
[0025] In this invention, the mass of the foaming agent is preferably 4.5 to 5.5% of the dry material mass, more preferably 4.6 to 5.4%, and even more preferably 4.8 to 5.2%.
[0026] In this invention, the mass ratio of foaming agent to foaming water is preferably 1:42~58, more preferably 1:45~55, and even more preferably 1:48~52.
[0027] In this invention, the water-to-binder ratio is preferably 0.35 to 0.45, more preferably 0.36 to 0.44, and even more preferably 0.38 to 0.42.
[0028] In this invention, the foaming agent is SD-SNFP foaming agent.
[0029] In this invention, the fly ash is Class F, Grade I fly ash.
[0030] In this invention, the particle size of the recycled micro powder is preferably ≤0.075mm, more preferably ≤0.07mm, and even more preferably ≤0.065mm.
[0031] In this invention, the recycled micro powder is obtained by processing waste concrete components. The waste concrete components are ball-milled for a time preferably ≥45 min, more preferably ≥50 min, and more preferably ≥60 min. After ball milling, the recycled micro powder is sieved to obtain recycled micro powder with a particle size that meets the requirements. The recycled micro powder is mainly composed of aggregate rock minerals such as SiO2, C2S, and C3S.
[0032] In this invention, the particle size of the desert sand is preferably 0.015~0.02mm, more preferably 0.016~0.019mm, and even more preferably 0.017~0.018mm; the fineness modulus is preferably 0.3~0.35, more preferably 0.31~0.34, and even more preferably 0.32~0.33.
[0033] In this invention, the desert sand is taken from Qarhan and is mainly composed of aggregate rock minerals such as SiO2, Al2O3, and Fe2O3. The particle morphology of the desert sand is characterized by rounded and nearly spherical shape.
[0034] The present invention also provides a method for preparing the desert sand foam concrete, comprising the following steps: (1) Mix the dry materials with the mixing water to obtain a slurry; (2) Mix the foaming agent and foaming water to obtain foam; (3) Add the foam to the slurry and mix and cure in sequence to obtain the desert sand foam concrete.
[0035] In this invention, the mixing speed in step (2) is preferably 1500~2000 rpm, more preferably 1600~1900 rpm, and even more preferably 1700~1800 rpm; the time is preferably ≥2 min, more preferably ≥4 min, and even more preferably ≥6 min.
[0036] In this invention, the mixing time in step (3) is preferably ≥5 min, more preferably ≥8 min, and even more preferably ≥10 min.
[0037] In this invention, the temperature for curing in step (3) is preferably 18~22℃, more preferably 19~21℃, and even more preferably 19.5~20℃; the humidity is preferably ≥95%, more preferably ≥96%, and even more preferably ≥97%.
[0038] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0039] Example 1
[0040] The dry materials are configured as follows: 10% recycled micro powder, 10% fly ash (Class F, Grade I fly ash), 10% desert sand, and 70% silicate cement.
[0041] Waste concrete components are ball-milled for 45 minutes, and the components with a particle size of less than 0.075 mm are screened to obtain recycled micro powder. The desert sand was taken from Qarhan, with a particle size of 0.019 mm and a fineness modulus of 0.327.
[0042] The mass of SD-SNFP foaming agent is 5% of the dry material mass, the mass ratio of foaming agent to foaming water is 1:50, and the water-to-binder ratio is controlled at 0.4.
[0043] The dry materials are mixed with mixing water to obtain a slurry. The foaming agent and foaming water are mixed and stirred at 1800 rpm for 2 minutes to obtain foam. The foam is added to the slurry and stirred for 5 minutes to obtain foam slurry. The foam slurry is poured into a standard test mold, vibrated and smoothed, covered with plastic film, and cured in a standard curing room (temperature 20℃, relative humidity ≥95%) for 24 hours before demolding. It is then cured for another 28 days to obtain desert sand foam concrete.
[0044] Example 2
[0045] The difference between this embodiment and Embodiment 1 is that the dry material contains 10% recycled micro powder, 15% fly ash, 20% desert sand, and 55% cement, while the rest is the same as in Embodiment 1.
[0046] Example 3
[0047] The difference between this embodiment and Embodiment 1 is that the dry material contains 10% recycled micro powder, 20% fly ash, 15% desert sand, and 55% cement, while the rest is the same as in Embodiment 1.
[0048] Example 4
[0049] The difference between this embodiment and Embodiment 1 is that the dry material contains 15% recycled micro powder, 10% fly ash, 20% desert sand, and 55% cement, while the rest is the same as in Embodiment 1.
[0050] Example 5
[0051] The difference between this embodiment and Embodiment 1 is that the dry material contains 15% recycled micro powder, 15% fly ash, 15% desert sand, and 55% cement, while the rest is the same as in Embodiment 1.
[0052] Example 6
[0053] The difference between this embodiment and Embodiment 1 is that the dry material contains 15% recycled micro powder, 20% fly ash, 10% desert sand, and 55% cement, while the rest is the same as in Embodiment 1.
[0054] Example 7
[0055] The difference between this embodiment and Embodiment 1 is that the dry material contains 20% recycled micro powder, 10% fly ash, 15% desert sand, and 55% cement, while the rest is the same as in Embodiment 1.
[0056] Example 8
[0057] The difference between this embodiment and Embodiment 1 is that the dry material contains 20% recycled micro powder, 15% fly ash, 10% desert sand, and 55% cement, while the rest is the same as in Embodiment 1.
[0058] Example 9
[0059] The difference between this embodiment and Embodiment 1 is that the dry material contains 20% recycled micro powder, 20% fly ash, 20% desert sand, and 40% cement, while the rest is the same as in Embodiment 1.
[0060] The performance of the desert sand foam concrete cured in Examples 1-9 was tested, and the results are recorded in Table 1.
[0061] Table 1 Performance Test Results
[0062] As shown in Table 1, the water absorption rate of Example 2 was as low as 4.1%, significantly improving the poor durability of foamed concrete; the water absorption rate of the concrete in Example 6 was 311.08 kg / m³. 3 At a density of 1.43 MPa, it achieves a high strength of 1.43 MPa and a low thermal conductivity of 0.023 W / m·K, demonstrating outstanding performance advantages.
[0063] The XRD patterns of concrete in Examples 1-9 are shown below. Figure 1 As shown in the figure, a large amount of hydrated calcium silicate (CSH) gel and ettringite (AFt) were generated in the sample, which is the main source of strength.
[0064] SEM images of Examples 4-6 are shown below. Figure 2 As shown, the sample has a uniform pore structure, small pore size, and dense pore walls. Desert sand particles and unreacted micro-powder particles fill the pores and between the gel, resulting in a good micro-aggregate filling effect, which explains its high strength and low thermal conductivity mechanism.
[0065] Comparative Example 1
[0066] The difference between Comparative Example 1 and Example 6 is that river sand was used instead of desert sand. The preparation and testing methods were the same as in Example 6. The test results showed that the compressive strength of Comparative Example 1 was approximately 1.1 MPa, the thermal conductivity was approximately 0.030 W / m·K, and the water absorption rate was approximately 9.5%. The overall performance was significantly worse than that of Example 6 of the present invention, which proves that the introduction of desert sand played a key role in performance optimization.
[0067] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A desert sand foam concrete, characterized in that, It is prepared from the following raw materials: Dry materials, foaming agent, foaming water, and mixing water; The dry material comprises the following components by mass percentage: Cement 40-70%, fly ash 10-20%, recycled powder 10-20%, desert sand 10-20%; The foaming agent should be 4-6% of the dry material weight. The mass ratio of foaming agent to foaming water is 1:40~60; The water-to-binder ratio is 0.3~0.
5.
2. The desert sand foam concrete as described in claim 1, characterized in that, The foaming agent is SD-SNFP foaming agent.
3. The desert sand foam concrete as described in claim 2, characterized in that, The fly ash is classified as Class F, Grade I fly ash.
4. The desert sand foam concrete as described in claim 3, characterized in that, The particle size of the recycled micro powder is ≤0.075mm; The particle size of desert sand is 0.015~0.02mm, and the fineness modulus is 0.3~0.
35.
5. The method for preparing desert sand foamed concrete according to any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Mix the dry materials with the mixing water to obtain a slurry; (2) Mix the foaming agent and foaming water to obtain foam; (3) Add the foam to the slurry and mix and cure in sequence to obtain the desert sand foam concrete.
6. The method for preparing desert sand foamed concrete as described in claim 5, characterized in that, The mixing time in step (3) is ≥5 min.
7. The method for preparing desert sand foamed concrete as described in claim 6, characterized in that, In step (3), the curing temperature is 18~22℃ and the humidity is ≥95%.