3D printing foam concrete composition, slurry and construction method of building structure

Abstract

The invention relates to a 3D printing foam concrete composition and slurry, and a construction method of a building structure, the 3D printing foam concrete composition comprises a powder material and a liquid material used for being mixed with the powder material; the powder material comprises the following components in parts by weight: 50-80 parts of Portland cement, 10-30 parts of phosphorus slag, 10-30 parts of carbide slag, 1-3 parts of a foaming agent, 1-2 parts of a foam stabilizer and 1-2 parts of a foaming catalyst; the liquid material is prepared from the following components in parts by weight: 20 to 40 parts of water, 0.06 to 0.12 part of a water reducing agent and 0.3 to 0.7 part of a thickening agent. The 3D printing foam concrete has the beneficial effects that after the 3D printing foam concrete is printed, the foam concrete is good in bubble stability and uniform in pore size distribution, so that the printable performance of a foam concrete material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and particularly to a 3D printing foam concrete composition and slurry, and a construction method of a building structure. Background Art

[0002] Concrete 3D printing technology is a new concrete construction process that has emerged in recent years, with high resource utilization rate, fast manufacturing speed, ability to create complex geometries, and low comprehensive cost. As an important part of green building materials, foam concrete is deeply loved by the construction industry. Foam concrete is a microporous material formed by mixing a prepared foam group, cement, admixtures, water, and other additive materials in a certain proportion. Foam concrete has performance advantages such as light weight, heat insulation, sound insulation, stability and reliability, and can reduce the self-weight of buildings. Combining the emerging 3D printing technology with foam concrete can not only give full play to the advantages of the materials themselves, but also achieve complex shape design.

[0003] However, the existing foam concrete has disadvantages such as poor foam stability, uneven pore distribution, low compressive strength, and large shrinkage after 3D printing, resulting in problems such as easy deformation and cracking of the printed material after placement, affecting the volume stability and durability of 3D printed components; at the same time, the raw material cost of existing 3D printed foam concrete is generally high, restricting the popularization and application of concrete 3D printing technology. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] In view of the above-mentioned disadvantages and deficiencies of the prior art, the present invention provides a 3D printing foam concrete composition and slurry, and a construction method of a building structure, which solve the technical problems such as poor foam stability, uneven pore distribution, low compressive strength, and large shrinkage of foam concrete after 3D printing.

[0006] (2) Technical Solutions

[0007] To achieve the above object, the main technical solutions adopted by the present invention include:

[0008] In the first aspect, an embodiment of the present invention provides a 3D printing foam concrete composition, including powder materials and liquid materials for mixing with the powder materials; the powder materials include, by weight: 50 - 80 parts of portland cement, 10 - 30 parts of phosphorus slag, 10 - 30 parts of carbide slag, 1 - 3 parts of foaming agent, 1 - 2 parts of foam stabilizer, and 1 - 2 parts of foaming catalyst; the liquid materials include, by weight: 20 - 40 parts of water, 0.06 - 0.12 parts of water reducer, and 0.3 - 0.7 parts of thickening agent.

[0009] Preferably, the powder material and the liquid material are separately packaged, and the powder material and the liquid material are mixed and foamed during use to obtain 3D printing foam concrete.

[0010] As a preferred embodiment of the present invention, in the 3D printing foam concrete composition, the mass ratio of phosphorus slag to carbide slag is 1-3:1-3; the total mass of phosphorus slag and carbide slag accounts for 30%-60% of the mass of Portland cement.

[0011] As a preferred embodiment of the present invention, in the 3D printing foam concrete composition, after the powder material and the liquid material are mixed and foamed, 3D printing foam concrete slurry is prepared, and its water-cement ratio is 0.28-0.35. Among them, the water-cement ratio is the mass ratio of water to the total mass of P·II 42.5 Portland cement, phosphorus slag and carbide slag.

[0012] As a preferred embodiment of the present invention, the 3D printing foam concrete composition

[0013] In the powder material, the foaming agent is solid hydrogen peroxide crystal powder, in which the H2O2 content is 30-35wt%; the foaming catalyst is manganese dioxide catalyst, in which the MnO2 content is 20-25wt%;

[0014] The foam stabilizer is selected from one or more combinations of sodium dodecylbenzenesulfonate, xanthan gum and calcium stearate, that is, the foam stabilizer is selected from at least one of anionic surfactant type, biopolymer type thickener and nonionic surfactant type; the Portland cement is P·II 42.5 Portland cement.

[0015] As a preferred embodiment of the present invention, in the 3D printing foam concrete composition, the particle size range of Portland cement is 5-50μm, and the average particle size is 14-15μm;

[0016] The particle size range of phosphorus slag is 5-100μm, and the average particle size is 16-17.5μm;

[0017] The particle size range of carbide slag is 3-50μm, and the average particle size is 6-7μm.

[0018] As a preferred embodiment of the present invention, in the 3D printing foam concrete composition, in the liquid material, the water reducing agent is polycarboxylic acid water reducing agent or polyphosphoric acid water reducing agent; the thickener is selected from hydroxypropyl methyl cellulose ether or sodium carboxymethyl cellulose.

[0019] Second aspect, an embodiment of the present invention provides a method for preparing a 3D printing foam concrete slurry, including the following steps: S1. Material preparation: Weigh powders, where the powders include 50 - 80 parts by weight of portland cement, 10 - 30 parts of phosphorus slag, 10 - 30 parts of carbide slag, 1 - 2 parts of foam stabilizer, and 1 - 2 parts of foaming catalyst, and mix the powders evenly; Measure water according to a water-cement ratio of 0.28 - 0.35, and weigh 0.06 - 0.12 parts by weight of water reducer, 0.3 - 0.7 parts by weight of thickener, and 1 - 3 parts by weight of foaming agent;

[0020] S2. Mix water and the water reducer to obtain a mixed liquid, and mix the mixed liquid with the evenly mixed powders to obtain a slurry;

[0021] S3. Add the foaming agent to the slurry, mix evenly, foam, and add the thickener to adjust the viscosity to obtain a 3D printing foam concrete slurry.

[0022] As a preferred embodiment of the present invention, in the method for preparing the 3D printing foam concrete slurry, in S2, the process of mixing the mixed liquid and the powders is as follows: First, stir at 60 - 70 r / min for 120 - 180 s, and then stir at 125 - 130 r / min for 60 - 120 s;

[0023] In S3, the process of mixing the foaming agent and the slurry is as follows: First, stir at 60 - 70 r / min for 120 - 180 s, and then stir at 125 - 130 r / min for 60 - 120 s.

[0024] Third aspect, an embodiment of the present invention provides a construction method for a building structure, including the following steps:

[0025] Step 1. Use the 3D printing foam concrete slurry prepared by the preparation method described in any one of claims 7 - 8, and obtain a building structure through 3D printing;

[0026] Or use the 3D printing foam concrete composition described in any one of claims 1 - 6. After making the composition into a 3D printing foam concrete slurry, then obtain a building structure through 3D printing;

[0027] Step 2. Subject the building structure to normal curing and carbonation curing to obtain a building structure.

[0028] As a preferred embodiment of the present invention, in the construction method for the building structure, in step 2, the normal curing conditions are curing at room temperature for 24 h;

[0029] The carbonation curing conditions are: using CO2 gas with a concentration of 18% - 100%, curing for 3 - 14 d under the conditions of 0 - 1.2 MPa, 20 - 60 °C, and a relative humidity of 50% - 70%.

[0030] (III) Advantageous Effects

[0031] The advantageous effects of the present invention are as follows: For the 3D printing foam concrete composition, slurry, and construction method of the building structure of the present invention, based on portland cement as the main material, phosphorous slag is used as an auxiliary raw material and carbide slag is used as an alkaline activator, and a specific dosage ratio relationship is adopted among the three. Among them, carbide slag provides an alkaline environment as a calcium hydroxide source, and a large amount of calcium hydroxide can effectively promote the pozzolanic reaction involving phosphorous slag in the foam concrete system: calcium hydroxide reacts with the reactive silica and reactive alumina in phosphorous slag to generate a more dense and stable calcium aluminosilicate hydrate (C(A)SH). At the same time, a pozzolanic reaction also occurs between phosphorous slag and portland cement, further enhancing the stability of the foam concrete system. In addition, the reactive alumina in phosphorous slag reacts with carbide slag to form ettringite, which provides more products for carbonation during the later curing process of the foam concrete body. Considering the above factors, the strength and durability of the 3D printing foam concrete material are improved. Tests have proved that the 14-day strength of the specimens all reaches above about 17 MPa, meeting the mechanical requirements of building components. Phosphorous slag can also accelerate the carbonation rate of 3D printing foam concrete. By combining a foaming agent and a foaming catalyst, the application performance of the 3D printing material is optimized, so that after the 3D printing foam concrete is printed, its bubble stability is good and the pore size distribution is uniform, thus improving the printability of the foam concrete material.

[0032] Adding 0.06 - 0.12 parts of water reducing agent can disperse particles through electrostatic repulsion and steric hindrance effects, significantly improving fluidity. The fluidity is basically in the range of 160 - 180 mm. The foam concrete meets the pumpability requirements and can be evenly and continuously extruded from the printing nozzle, and can be used for 3D printing. Incorporating 0.3 - 0.7 parts of thickening agent can increase the viscosity of the slurry and endow thixotropy, so that it maintains a high viscosity when static and the viscosity decreases during shearing (such as during printing extrusion). The phosphorous slag micropowder fills the interfacial layer between layers, reduces pores, and the C-S-H gel penetrates into the lower layer to form chemical bonds, enhancing the interfacial bonding force between layers. Generally, the foam concrete material meets the requirements of the 3D printing process for fluidity, extrudability, setting time, and interfacial bonding between layers, adapts to the requirements of extrusion, stacking, and rapid prototyping in the 3D printing process, and can achieve continuous printing and the construction of complex building structures.

[0033] Compared with the prior art, the 3D printing foam concrete has the characteristics of high stability and relatively high carbon sequestration effect. The corresponding 3D printing material has the advantages of good bubble stability, uniform pore size distribution, high concrete strength, small shrinkage, and good printability. The raw materials phosphorous slag and carbide slag are both solid wastes, with wide sources and low costs. Their preparation methods are simple and convenient, and are easy for industrial production.

[0034] The foaming agent is selected as solid hydrogen peroxide crystal powder. The combination of the foaming agent and the catalyst manganese dioxide optimizes the application performance of the 3D printing material. The foam concrete prepared from the solid hydrogen peroxide crystal powder has the advantages of good bubble stability, uniform pore size distribution, high concrete strength, small shrinkage, and good printability.

[0035] The particle size of ordinary Portland cement is 0.62 - 420 μm, the particle size of phosphorus slag is 0.58 - 157 μm, and the average particle size of carbide slag is 10 - 30 μm, which is beneficial to activating active substances to participate in the reaction in the water environment. The thickening agent is selected as a fiber thickening agent, which disperses stress through molecular chain entanglement and inhibits the crack propagation of foam concrete. Description of the Drawings

[0036] Figure 1 This is the building structure prepared in Example 4 of the present invention. Detailed Implementation Modes

[0037] In order to better explain the present invention for easy understanding, the present invention will be described in detail below with reference to the drawings and through specific implementation modes.

[0038] The 3D printing foam concrete composition, slurry, and construction method of the building structure proposed in the embodiments of the present invention aim at the technical problems existing in foam concrete after 3D printing, such as poor foam stability, uneven pore distribution, low compressive strength, and large shrinkage. The 3D printing foam concrete composition, slurry, and construction method of the present invention are based on Portland cement as the main material, with phosphorus slag as the auxiliary raw material and carbide slag as the alkaline activator, and a specific dosage ratio relationship is adopted among the three. Among them, carbide slag provides an alkaline environment as a calcium hydroxide source, and a large amount of calcium hydroxide can effectively promote the pozzolanic reaction participated by phosphorus slag in the foam concrete system: calcium hydroxide reacts with active silica and active alumina in phosphorus slag to generate more dense and stable calcium aluminosilicate hydrate (C(A)SH). At the same time, a pozzolanic reaction also occurs between phosphorus slag and Portland cement, further enhancing the stability of the foam concrete system. In addition, the active alumina in phosphorus slag reacts with carbide slag to generate ettringite, which provides more products for carbonation during the later curing process of the foam concrete body. Considering the above factors, the strength and durability of the 3D printing foam concrete material are improved. Tests have proved that the strength of the specimens reaches more than 20 MPa after 14 days, meeting the mechanical requirements of building components. Phosphorus slag can also accelerate the carbonation rate of 3D printing foam concrete. The combination of a foaming agent and a foaming catalyst optimizes the application performance of the 3D printing material, making the bubble stability of the 3D printing foam concrete good and the pore size distribution uniform after printing, thus improving the printability of the foam concrete material.

[0039] To better understand the above technical solution, the exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0040] Example 1

[0041] This example provides a 3D printed foamed concrete and its preparation method, which specifically includes the following steps:

[0042] (1) By weight, respectively weigh the following powder components: 60 parts of P·II 42.5 ordinary Portland cement, 20 parts of phosphorous slag, 20 parts of carbide slag, 1 part of sodium dodecylbenzenesulfonate (foam stabilizer), 1 part of manganese dioxide (catalyst), and 0.5 part of hydroxypropyl methylcellulose ether (thickener). Mix the above powder components, and then stir for 60 - 120 s to fully mix and obtain a well-mixed powder.

[0043] (2) Based on the mass of the powder, take water according to the mass ratio of water to the total mass of P·II 42.5 ordinary Portland cement, phosphorous slag, and carbide slag (water-cement ratio) of 0.3, and take 0.09 part of polycarboxylate standard type water reducer and mix it evenly in water to obtain a mixed solution.

[0044] (3) Mix the well-mixed powder with the mixed solution in step (2). First, stir in a mixer at 60 r / min for 120 - 180 s, and then stir at 125 r / min for 60 - 120 s to fully stir and obtain a slurry.

[0045] (4) Put 2.05 parts of solid hydrogen peroxide crystal powder (foaming agent, H2O2 content is 30%) into the slurry obtained in (3). First, stir in a mixer at 60 r / min for 120 - 180 s, and then stir at 125 r / min for 60 - 120 s to fully blend the foaming agent and the slurry, and obtain the slurry system of 3D printed foamed concrete.

[0046] Through X-ray fluorescence (XRF) analysis, in this example, the chemical components in Portland cement, phosphorous slag, and carbide slag are shown in Table 1:

[0047] Table 1 Chemical Components of Portland Cement, Phosphorous Slag, and Carbide Slag

[0048]

[0049] Example 2

[0050] This embodiment provides a 3D printed foamed concrete and its preparation method. The difference between this embodiment and Embodiment 1 is that in step (1), 30 parts of phosphorous slag and 10 parts of carbide slag are used.

[0051] Embodiment 3

[0052] This embodiment provides a 3D printed foamed concrete and its preparation method. The difference between this embodiment and Embodiment 1 is that in step (1), 10 parts of phosphorous slag and 30 parts of carbide slag are used.

[0053] Embodiment 4

[0054] This embodiment provides a construction method for a building structure, which specifically includes the following steps:

[0055] (1) Perform 3D printing on the slurry system of the 3D printed foamed concrete prepared in Embodiment 1 to print out a building structure; among them, the 3D printing process parameters are: a printing speed of 30 mm / s, a layer thickness of 1 mm, a line width of 1.5 mm, and an extrusion pressure of 0.5 MPa. Stack and print 40 layers layer by layer, and the printed sample size is a cube structure of 40 mm × 40 mm × 40 mm;

[0056] (2) Cure the building structure through ordinary curing and carbonation curing. The ordinary curing conditions are curing for 24 h at room temperature; the carbonation curing conditions are: in a CO2 gas atmosphere with a concentration of 18% - 100%, the curing pressure is 0 - 1.2 MPa, the curing temperature is 20 - 60 °C, the curing humidity is 50% - 70%, and the curing time is 14 d; finally, the Figure 1 shown building structure is obtained.

[0057] Embodiment 5

[0058] This embodiment provides a construction method for a building structure. The difference between this embodiment and Embodiment 4 is that in step (1), perform 3D printing on the slurry system of the 3D printed foamed concrete prepared in Embodiment 2 to print out a building structure. The remaining steps are the same as those in Embodiment 4.

[0059] Embodiment 6

[0060] This embodiment provides a construction method for a building structure. The difference between this embodiment and Embodiment 4 is that in step (1), perform 3D printing on the slurry system of the 3D printed foamed concrete prepared in Embodiment 3 to print out a building structure. The remaining steps are the same as those in Embodiment 4.

[0061] Comparative Example 1

[0062] This comparative example provides a 3D printed foamed concrete and its preparation method. The difference between this comparative example and Example 1 is as follows: In step (1), 40 parts of phosphorus slag are used, and no carbide slag is added. The remaining steps are the same as those in Example 1.

[0063] Comparative Example 2

[0064] This comparative example provides a 3D printed foamed concrete and its preparation method. The difference between this comparative example and Example 1 is as follows: In step (1), 20 parts of phosphorus slag are replaced with 20 parts of quartz, and 20 parts of carbide slag are used. The remaining steps are the same as those in Example 1.

[0065] Comparative Example 3

[0066] This comparative example provides a 3D printed foamed concrete and its preparation method. The difference between this comparative example and Example 1 is as follows: In step (1), no phosphorus slag is added, and 40 parts of carbide slag are used. The remaining steps are the same as those in Example 1.

[0067] Comparative Example 4

[0068] This comparative example provides a 3D printed foamed concrete and its preparation method. The difference between this comparative example and Example 1 is as follows: In step (1), 20 parts of phosphorus slag are used, and 20 parts of carbide slag are replaced with 20 parts of quartz. The remaining steps are the same as those in Example 1.

[0069] Comparative Example 5

[0070] This comparative example provides a construction method for a building structure. The difference between this comparative example and Example 4 is as follows: In step (1), the slurry system of the 3D printed foamed concrete prepared in Comparative Example 1 is used for 3D printing to print out a building structure. The remaining steps are the same as those in Example 4.

[0071] Comparative Example 6

[0072] This comparative example provides a construction method for a building structure. The difference between this comparative example and Example 4 is as follows: In step (1), the slurry system of the 3D printed foamed concrete prepared in Comparative Example 2 is used for 3D printing to print out a building structure. The remaining steps are the same as those in Example 4.

[0073] Comparative Example 7

[0074] This comparative example provides a construction method for a building structure. The difference between this comparative example and Example 4 is as follows: In step (1), the slurry system of the 3D printed foamed concrete prepared in Comparative Example 3 is used for 3D printing to print out a building structure. The remaining steps are the same as those in Example 4.

[0075] Comparative Example 8

[0076] This comparative example provides a construction method for a building structure. The difference between this comparative example and Example 4 is as follows: In step (1), the slurry system of the 3D printed foamed concrete prepared in Comparative Example 4 is 3D printed to print out a building structure body. The remaining steps are the same as those in Example 4.

[0077] For the building structure specimens prepared in Examples 4, 5, 6 and Comparative Examples 5, 6, 7, 8, compressive strength performance tests were carried out according to the ASTM C349 standard: The compressive strength of three specimens was tested using a hydraulic press and the average value was taken as the result. After testing, the compressive strength of the concrete specimens is shown in Table 2.

[0078] The slurry fluidity of the 3D printed foamed concrete prepared in Examples 1, 2, 3 and Comparative Examples 1, 2, 3, 4 was tested. The fluidity test results are shown in detail in Table 3.

[0079] For the building structure specimens prepared in Examples 4, 5, 6 and Comparative Examples 5, 6, 7, 8, porosity tests were carried out. The test results are shown in detail in Table 3; shrinkage rate tests were carried out with reference to JGJ70-2009 "Test Methods for Basic Properties of Building Mortars". The test results are shown in detail in Table 3; carbon sequestration rate tests were carried out with reference to "Calculation Method for Carbon Sequestration Capacity of Building Concrete throughout the Life Cycle". The test results are shown in detail in Table 3.

[0080] Table 2 Compressive Strength Test Results

[0081]

[0082]

[0083] Table 3 Test Results

[0084]

[0085] Result Analysis:

[0086] Referring to Table 2 and Table 3, Example 1 and the corresponding Example 4 are the best examples. Compared with Examples 5 and 6 corresponding to Examples 2 and 3, it shows that the best dosage ratio of carbide slag to phosphorus slag is 1:1. The total mass of carbide slag and phosphorus slag is about 2 / 3 of the mass of ordinary Portland cement, which greatly reduces the dosage of high-energy-consuming raw materials such as ordinary Portland cement. Carbide slag and phosphorus slag are solid waste utilization, which is economical and environmentally friendly.

[0087] Referring to Table 2, the compressive strength of the building structure body prepared in Example 4 is higher than that of Comparative Example 5, indicating that the addition of carbide slag provides a good alkali activation effect. Moreover, the active alumina in carbide slag and phosphorus slag can react to form hydration products mainly composed of ettringite. The hydration products are formed and continuously developed in the early stage, improving the compressive strength of the building structure body.

[0088] Referring to Table 2, it can be seen from Example 4 and Comparative Example 6 that when the same amount of quartz is used to replace phosphorus slag, the compressive strength of the building structure prepared in Example 4 is higher than that in Comparative Example 6. The reason is that the addition of phosphorus slag can not only accelerate the carbonation rate, but also react with calcium hydroxide to form calcium aluminosilicate hydrate. Moreover, the reactive alumina in phosphorus slag reacts with carbide slag to form ettringite, providing more products for solidifying carbonation, and finally improving the compressive strength of the building structure.

[0089] Referring to Table 2, the early compressive strength of Comparative Example 5 is less than that of Comparative Example 7, but the late compressive strength of Comparative Example 5 is significantly greater than that of Comparative Example 7. The reason is that the addition of phosphorus slag reduces the early heat of hydration and the amount of chemically bound water, slows down the heat release rate of hydration, has a retarding effect, inhibits the early hydration of cement, makes the crystal growth conditions develop well, thus significantly improving the quality of hydration products, making the cement stone structure more dense, the porosity decrease, and the pore size become smaller, which is very beneficial to the development of the later strength of concrete, and enables the later strength of concrete to be improved.

[0090] Referring to Table 2, it can be seen from Example 4 and Comparative Example 8 that the compressive strength of the building structure prepared in Example 4 is significantly higher than that in Comparative Example 8, that is, replacing carbide slag with quartz cannot achieve the alkali activation effect of carbide slag. Further proof shows that the activity of phosphorus slag is excited after adding carbide slag, producing a high-efficiency pozzolanic effect, generating a large amount of hydrated cementitious materials to fill the pores, correspondingly compensating for part of the dry shrinkage caused by pore water loss, and improving the shrinkage situation of concrete. Thus, the compressive strength of concrete is improved.

[0091] Referring to Table 3, the fluidity, shrinkage rate, cumulative carbon sequestration rate and porosity of the building structures prepared in Examples 4 - 6 are all better than those in Comparative Examples 5 - 8. The reaction between carbide slag and phosphorus slag improves the compressive strength of the building structure. In addition, the combined action of water, water reducer and thickener in foamed concrete makes the foamed concrete slurry meet the requirements of 3D printing process for fluidity, extrudability, setting time and interlayer bonding. It adapts to the requirements of extrusion, stacking and rapid prototyping, and realizes continuous printing and construction of complex structures.

[0092] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A 3D printing foamed concrete composition, characterized in that It includes powder materials and liquid materials for mixing with the powder materials; The powder materials include, by weight parts: 50 - 80 parts of portland cement, 10 - 30 parts of phosphorus slag, 10 - 30 parts of carbide slag, 1 - 3 parts of foaming agent, 1 - 2 parts of foam stabilizer, and 1 - 2 parts of foaming catalyst; The liquid materials include, by weight parts: 20 - 40 parts of water, 0.06 - 0.12 parts of water - reducing agent, and 0.3 - 0.7 parts of thickening agent.

2. The 3D printing foam concrete composition according to claim 1, wherein The mass ratio of phosphorus slag to carbide slag is 1 - 3:1 - 3; The total mass of phosphorus slag and carbide slag accounts for 30% - 60% of the mass of portland cement.

3. The 3D printing foam concrete composition according to claim 1, wherein, The powder materials and the liquid materials are mixed and foamed to obtain 3D - printed foam concrete slurry, and its water - cement ratio is 0.28 - 0.

35.

4. The 3D - printed foam concrete composition according to claim 1, characterized in that In the powder materials, the foaming agent is solid hydrogen peroxide crystal powder, wherein the H2O2 content is 30 - 35wt%; The foaming catalyst is manganese dioxide catalyst, wherein the MnO2 content is 20 - 25wt%; The foam stabilizer is selected from one or a combination of two or more of sodium dodecylbenzenesulfonate, xanthan gum, and calcium stearate; The portland cement is P·II 42.5 ordinary portland cement.

5. The 3D - printed foam concrete composition according to claim 4, characterized in that The particle size range of the ordinary portland cement is 5 - 50μm, and the average particle size is 14 - 15μm; The particle size range of the phosphorus slag is 5 - 100μm, and the average particle size is 16 - 17.5μm; The particle size range of the carbide slag is 3 - 50μm, and the average particle size is 6 - 7μm.

6. The 3D printing foamed concrete composition according to claim 1, wherein In the liquid materials, the water - reducing agent is polycarboxylate water - reducing agent or polyphosphate water - reducing agent; the thickening agent is selected from hydroxypropyl methylcellulose ether or sodium carboxymethylcellulose.

7. A method for preparing a 3D printing foam concrete slurry, characterized in that, It includes the following steps: S1. Preparation of materials: Weigh the powder materials, which contain, by weight parts: 50 - 80 parts of portland cement, 10 - 30 parts of phosphorus slag, 10 - 30 parts of carbide slag, 1 - 2 parts of foam stabilizer, 1 - 2 parts of foaming catalyst, and mix the powder materials evenly; Measure water according to the water - cement ratio of 0.28 - 0.35, and weigh 0.06 - 0.12 weight parts of water - reducing agent, 0.3 - 0.7 weight parts of thickening agent, and 1 - 3 weight parts of foaming agent; S2. Mix the water and the water - reducing agent to obtain a mixed liquid, and mix the mixed liquid with the evenly - mixed powder materials to obtain a slurry; S3. Add the foaming agent into the slurry, mix evenly, foam, and add the thickening agent to adjust the viscosity to obtain 3D - printed foam concrete slurry.

8. The preparation method of the 3D printing foam concrete slurry according to claim 7, wherein In S2, the process of mixing the mixed liquid and the powder materials is: first stir at 60 - 70r / min for 120 - 180s, and then stir at 125 - 130r / min for 60 - 120s; In S3, the process of mixing the foaming agent and the slurry is: first stir at 60 - 70r / min for 120 - 180s, and then stir at 125 - 130r / min for 60 - 120s.

9. A construction method of a building structure, characterized in that, It includes the following steps: Step 1. The 3D - printed foam concrete slurry prepared by the preparation method described in any one of claims 7 - 8 is used for 3D printing to obtain a building structure; Alternatively, use the 3D printing foam concrete composition described in any one of claims 1-6. After making the composition into a 3D printing foam concrete slurry, a building structure is obtained through 3D printing; Step 2: Subject the building structure to normal curing and carbonation curing to obtain a building structure.

10. The construction method of the building structure according to claim 9, characterized in that, In step 2, the normal curing conditions are curing at room temperature for 24 h; The carbonation curing conditions are: curing for 3-14 d under the conditions of using CO2 gas with a concentration of 18%-100%, at 0-1.2 MPa, 20-60 °C, and a relative humidity of 50%-70%.

Images