Underwater 3D printing material

Abstract

Belonging to the field of building materials, the invention discloses an underwater 3D printing material, which comprises water, cement, silica fume, nano calcium carbonate, sea mud powder, red mud fine aggregate, a naphthalene sulfonate water reducer and sodium polyethylene. Wherein the dosage of the sea mud powder is 106.5-170.4 kg / m < 3 >, the dosage of the red mud fine aggregate is 723.6-804.0 kg / m < 3 >, the dosage of the naphthalene sulfonate water reducer is 58.3-58.9 kg / m < 3 >, and the dosage of the sodium polyethylene acid is 0.7-1.3 kg / m < 3 >; by optimizing the multi-element synergistic effect of the functional material and the solid waste material, the material suitable for underwater 3D printing is provided, and the printing performance and mechanical strength of the underwater printing material are remarkably improved while efficient utilization of marine resources and regeneration of solid waste resources are achieved.

Description

Technical Field

[0001] The present invention relates to the field of building materials, and in particular to an underwater 3D printing material. Background Art

[0002] In recent years, guided by the strategies of building a strong maritime nation and the dual carbon strategy, the efficient development of marine resources and the resource utilization of solid waste have become key national strategic priorities. If abundant seawater and solid waste resources such as red mud and sea mud could be used as building materials, they would undoubtedly play a significant role in reducing construction costs and achieving environmental protection and carbon reduction. At the same time, the application of 3D printing technology in the construction field is increasing, and research on cement-based materials suitable for this technology is also deepening. The successful development of new solid waste-based underwater 3D printing materials would not only significantly reduce the high costs and environmental risks of traditional underwater construction, but also achieve the recycling of solid waste resources, injecting new momentum into the blue economy and ushering in a new era for marine engineering.

[0003] Unlike traditional land-based 3D printing, underwater 3D printing has higher requirements for concrete materials. The underwater environment can easily cause ordinary mortar to quickly disperse and fail, making it difficult to print and shape, and it is also difficult to achieve the required strength. Therefore, research on the preparation and mechanical properties of underwater 3D printed concrete for underwater engineering has important significance and engineering value. Summary of the Invention

[0004] In response to the above problems, the present invention optimizes the multi-factor synergistic effects of functional materials and solid waste materials to provide a material suitable for underwater 3D printing. While achieving efficient utilization of marine resources and regeneration of solid waste resources, it significantly improves the printing performance and mechanical strength of underwater printing materials.

[0005] The purpose of the present invention is achieved by adopting the following technical solutions: An underwater 3D printing material, comprising water, cement, silica fume, nano-calcium carbonate, sea mud powder, red mud fine aggregate, naphthalenesulfonate water reducer and sodium polyacrylate; wherein the amount of the sea mud powder is 106.5-170.4 kg / m 3 The amount of red mud fine aggregate is 723.6-804.0kg / m 3 The dosage of the naphthalenesulfonate water reducer is 58.3-58.9 kg / m 3 The dosage of sodium polyacrylate is 0.7-1.3 kg / m 3 .

[0006] In some preferred embodiments, the amount of water used is 244.8 kg / m 3 The amount of cement used is 901.9 kg / m 3 The amount of silica fume used is 143.0 kg / m3 The dosage of the nano calcium carbonate is 13.5 kg / m 3 .

[0007] In some preferred embodiments, the water is seawater.

[0008] In some preferred embodiments, the cement is 42.5R Portland cement.

[0009] In some preferred embodiments, the average particle size of the silica fume is 0.1-0.3 μm.

[0010] In some preferred embodiments, the nano-calcium carbonate is a hydrophilic powder with an average particle size of 50 nm.

[0011] In some preferred embodiments, the sea mud powder is obtained by drying and grinding the sea mud, and has a maximum particle size of 0.6 mm.

[0012] In some preferred embodiments, the red mud fine aggregate is obtained by drying and sieving Bayer red mud, and has a maximum particle size of 1.2 mm.

[0013] In some preferred embodiments, the solid content of the naphthalenesulfonate-based water reducer is 37%.

[0014] In some preferred embodiments, the average molecular weight of the sodium polyacrylate is 500,000 g / mol.

[0015] The beneficial effects of the present invention are: The present invention provides a material suitable for underwater 3D printing by optimizing the multi-factor synergistic effects of functional materials and solid waste materials. While achieving efficient utilization of marine resources and regeneration of solid waste resources, it significantly improves the printing performance and mechanical strength of underwater printing materials. Specifically, the present invention utilizes high-molecular-weight sodium poly(polyvinyl)ate to effectively improve the underwater anti-dispersion properties of cement-based materials through multiple mechanisms such as molecular chain entanglement, hydration film thickening, and particle adsorption; utilizes the high specific surface area of ​​silica fume to absorb water, thereby improving the underwater cohesion of cement-based materials; simultaneously utilizes the volcanic ash activity and ultrafine particle filling effect of silica fume to achieve secondary hydration and microstructural density, thereby improving strength performance; utilizes the extremely large specific surface area of ​​nano-calcium carbonate to absorb water, effectively enhancing the water retention and cohesion properties of the system; its crystal nucleation effect, combined with the filling effect of ultrafine particles, not only promotes the early hydration process, but also improves the structural density, thereby contributing to further strength improvement.

[0016] The present invention successfully integrates seawater and solid waste resources, significantly improving the environmental friendliness and economic applicability of the material. First, it is suitable for seawater mixing, and seawater can be used directly to prepare the mixture in the offshore operation area, reducing the cost of raw material input and significantly improving the efficiency and convenience of on-site construction. Second, red mud fine aggregate replaces traditional natural aggregate, improving the utilization rate of solid waste, reducing carbon footprint, and having cost advantages. Third, the addition of sea mud powder not only realizes its resource recycling, but also, due to its weak acidity, helps to adjust the alkalinity of the printing material, thereby improving the environmental friendliness of the material system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is further described with reference to the accompanying drawings. However, the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative effort.

[0018] Figure 1 This is a diagram of the underwater printing process of the material described in Example 1 of the present invention; Figure 2 This is a diagram of an underwater printing test piece of the material described in Example 1 of the present invention; Figure 3 This is a diagram of an underwater printing test piece of the material described in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described with reference to the following examples.

[0020] Example 1 An underwater 3D printing material, consisting of water, cement, silica fume, nano calcium carbonate, sea mud powder, red mud fine aggregate, naphthalenesulfonate water reducer and sodium polyacrylate, wherein: The water is seawater with a specific gravity of 1.02 and a dosage of 244.8 kg / m 3 ; The strength grade of the cement is 42.5 (Shijing brand), the specific gravity is 3.11, and the dosage is 901.9 kg / m 3 ; The silica fume is produced by East Bluestar Company, with a SiO2 content of more than 90%, an average particle size of 0.1-0.3 μm, a specific gravity of 2.20, and a dosage of 143.0 kg / m 3 ; The nano calcium carbonate was produced by Shanghai MacLean Biochemical Technology Co., Ltd., with an average particle size of 50 nm and a specific gravity of 2.70. The dosage was 13.5 kg / m 3 ; The sea mud powder is obtained from the coastal area of ​​Zhuhai City through drying and ball milling. The maximum particle size is 0.6mm, the specific gravity is 2.13, and the dosage is 106.5kg / m 3 ; The red mud fine aggregate was obtained from the red mud dump of China Aluminum Corporation in Pingguo City, Guangxi, and was obtained by drying and screening. The maximum particle size was 1.2 mm, the specific gravity was 2.68, and the dosage was 804.0 kg / m 3 , The naphthalenesulfonate water reducer is produced by Zhaoqun Development Co., Ltd., with a solid content of 37%, a specific gravity of 1.19, and a dosage of 58.3 kg / m 3 ; The sodium polyacrylate is produced by Shanghai MacLean Biochemical Technology Co., Ltd., with an average molecular weight of 500,000 g / mol, a specific gravity of 1.30, and a dosage of 1.3 kg / m 3 .

[0021] Example 2 An underwater 3D printing material, similar to Example 1, except that the weight ratio of each raw material is: Seawater 244.8kg / m 3 , cement 901.9kg / m 3 、Silica fume 143.0kg / m 3 , nano calcium carbonate 13.5kg / m 3 , sea mud powder 170.4kg / m 3 , red mud fine aggregate 723.6kg / m 3 , naphthalenesulfonate water reducer 58.9kg / m 3 , sodium polyacrylate 0.7kg / m 3 .

[0022] Comparative Example 1 A mixture, compared to Example 1, wherein the mixture does not include silica fume, nano-calcium carbonate and sodium polyacrylate, and the weight ratio of the raw materials is: Seawater 244.8kg / m 3 、Cement 1119.6kg / m 3 , sea mud powder 106.5kg / m 3 , red mud fine aggregate 804.0kg / m 3 , naphthalenesulfonate water reducer 59.5kg / m 3 .

[0023] Comparative Example 2 A mixture, compared to Example 1, wherein the mixture does not include sea mud powder and red mud fine aggregate, but uses conventional river sand fine aggregate (maximum particle size 1.18 mm); the weight ratio of the raw materials is: Seawater 244.8kg / m 3 , cement 901.9kg / m 3 、Silica fume 143.0kg / m 3 , nano calcium carbonate 13.5kg / m3 , river sand fine aggregate 927.5kg / m 3 , naphthalenesulfonate water reducer 58.3kg / m 3 , sodium polyacrylate 1.3kg / m 3 .

[0024] Comparative Example 3 A mixture, compared to Example 1, does not include silica fume, nano-calcium carbonate, and sodium polyacrylate, nor does it include sea mud powder and red mud fine aggregate, but instead uses conventional river sand fine aggregate (maximum particle size 1.18 mm); the weight ratio of the raw materials is: Seawater 244.8kg / m 3 、Cement 1119.6kg / m 3 , river sand fine aggregate 927.5kg / m 3 , naphthalenesulfonate water reducer 59.5kg / m 3 .

[0025] Experimental example (1) The composition ratios of the materials described in Examples 1-2 and Comparative Examples 1-3 are shown in Table 1.

[0026] Table 1 Composition ratio of the materials described in Examples 1-2 and Comparative Examples 1-3

[0027] (2) The printing performance of the materials described in Examples 1-2 and Comparative Examples 1-3 is shown in Table 2. Figure 2 、 Figure 3As can be seen, the jump table expansion of Examples 1 and 2 is moderate, at 143-150 mm. They can be fully formed underwater without unraveling, demonstrating excellent underwater anti-dispersion properties. The coefficients of variation for extrudability (0.81% and 0.73%) and buildability (0.78% and 0.66%) are very low, indicating good underwater printing quality. In contrast, the jump table expansion of Comparative Example 1, which does not use silica fume, nano-calcium carbonate, and sodium polyacrylate, is larger at 194 mm. It exhibits severe underwater unraveling, making it impossible to stack and form, demonstrating poor anti-dispersion properties. The coefficient of variation for extrudability is as high as 4.87%, resulting in buildability failure (i.e., inability to stack), indicating that underwater printing is unsuccessful. In Comparative Example 2, which used conventional river sand fine aggregate instead of sea mud powder and red mud fine aggregate, the jump table expansion was slightly larger at 171 mm. While stackable and printable underwater, slight dispersion occurred. The extrudability coefficient of variation and buildability coefficient of variation were 2.11% and 2.73%, respectively, significantly higher than those in the Example, indicating average underwater printing quality. In Comparative Example 3, which used no silica fume, nano-calcium carbonate, sodium polyacrylate, sea mud powder, or red mud fine aggregate, the jump table expansion reached a maximum of 221 mm. The product severely dispersed underwater, unable to be stacked and formed, indicating poor anti-dispersion properties. The extrudability coefficient of variation was the highest at 6.12%, resulting in a buildability failure (i.e., inability to stack), indicating that underwater printing was unsuccessful.

[0028] Table 2 Printing performance of the materials described in Examples 1-2 and Comparative Examples 1-3

[0029] (3) The mechanical properties of underwater printed parts of the materials described in Examples 1-2 and Comparative Examples 1-3 are shown in Table 3. As can be seen from Table 3, Examples 1 and 2 have higher flexural strength (7.8 and 6.9 MPa) and compressive strength (45.7 and 41.1 MPa), and because they can be printed and formed, their interlayer bonding strengths of 3.4 and 2.9 MPa can be measured. However, the flexural strength (3.1 MPa) and compressive strength (21.4 MPa) of Comparative Example 1 are significantly lower than those of the Examples, and due to the failure of the construction, the interlayer bonding strength cannot be obtained. For Comparative Example 2, its flexural strength (7.1 MPa) and compressive strength (43.2 MPa) are similar to those of the Examples, but the interlayer bonding strength (1.1) is lower than that of the Examples. For Comparative Example 3, both the flexural strength (4.1 MPa) and compressive strength (23.0 MPa) are significantly lower than those of the Examples, and due to the failure of the construction, the interlayer bonding strength cannot be obtained.

[0030] Table 3 Mechanical properties of underwater printed parts of the materials described in Examples 1-2 and Comparative Examples 1-3

[0031] In addition, from the perspective of solid waste utilization, Examples 1 and 2 used a large amount of sea mud and red mud solid waste, while Comparative Examples 2 and 3 used non-renewable natural river sand aggregate. Obviously, Examples 1 and 2 have better environmental benefits.

[0032] In summary, the underwater 3D printing material of the embodiment not only has good underwater printing performance, but also has high mechanical properties and makes extensive use of solid waste, thus demonstrating excellent comprehensive benefits.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An underwater 3D printing material, characterized in that: The invention comprises water, cement, silica fume, nano calcium carbonate, sea mud powder, red mud fine aggregate, naphthalenesulfonate water reducer and sodium polyacrylate; wherein the amount of the sea mud powder is 106.5-170.4 kg / m 3 The amount of red mud fine aggregate is 723.6-804.0kg / m 3 The dosage of the naphthalenesulfonate water reducer is 58.3-58.9 kg / m 3 The dosage of sodium polyacrylate is 0.7-1.3 kg / m 3 .

2. The underwater 3D printing material according to claim 1, characterized in that: The amount of water used is 244.8 kg / m 3 The amount of cement used is 901.9 kg / m 3 The amount of silica fume used is 143.0 kg / m 3 The dosage of the nano calcium carbonate is 13.5 kg / m 3 .

3. An underwater 3D printing material according to claim 1 or 2, characterized in that: The water is seawater.

4. An underwater 3D printing material according to claim 1 or 2, characterized in that: The cement is 42.5R Portland cement.

5. The underwater 3D printing material according to claim 1 or 2, characterized in that: The average particle size of the silica fume is 0.1-0.3 μm.

6. An underwater 3D printing material according to claim 1 or 2, characterized in that: The nano calcium carbonate is a hydrophilic powder with an average particle size of 50 nm.

7. The underwater 3D printing material according to claim 1 or 2, characterized in that: The sea mud powder is obtained by grinding the dried sea mud, and has a maximum particle size of 0.6 mm.

8. The underwater 3D printing material according to claim 1 or 2, characterized in that: The red mud fine aggregate is obtained by drying and screening Bayer red mud, and has a maximum particle size of 1.2 mm.

9. The underwater 3D printing material according to claim 1 or 2, characterized in that: The solid content of the naphthalenesulfonate-based water reducer is 37%.

10. The underwater 3D printing material according to claim 1 or 2, characterized in that: The average molecular weight of the sodium polyacrylate is 500,000 g / mol.

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