Anti-carbonization low-carbon slag powder cement material and application thereof

Abstract

The invention relates to the technical field of low-carbon cement preparation, and particularly discloses an anti-carbonization type low-carbon slag powder cement material and application thereof. The cement material comprises the following components in parts by weight: 55-75 parts of slag powder, 15-25 parts of gypsum powder, 3-10 parts of a cement gelling component, 1-3 parts of spinel powder and 2-5 parts of an anti-carbonization agent, wherein the anti-carbonization agent is formed by mixing polyferric sulfate, water-soluble phosphate and water-soluble carbonate according to the mass ratio of (7-10): (3-5): 1. The anti-carbonization type low-carbon slag powder cement material does not cause the risk of alkali aggregate reaction and does not depend on a nano material, so that the anti-carbonization performance of the low-carbon slag powder cement is improved, and the mechanical property of the low-carbon slag powder cement is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of low-carbon cement preparation, and in particular to a carbonization-resistant low-carbon slag powder cement material and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] The cement industry, a high-carbon-emitting sector, contributes approximately 8% of global CO2 emissions, necessitating the development of low-carbon cementitious materials. Blast furnace slag powder, an industrial byproduct, is considered a key resource for replacing cement clinker due to its pozzolanic activity and low environmental impact. Currently, slag powder can be incorporated into cement at a rate of 30-70%. While this significantly reduces the amount of cement clinker used, and thus indirectly reduces carbon emissions, the carbonation problem associated with high-slag powder cement severely restricts its practical application.

[0004] The essence of carbonation is that environmental CO2 intrudes into concrete and reacts with cement hydration products to form water-soluble carbonates, which causes the pH value to drop, thereby causing steel corrosion and structural deterioration. Studies have shown that when the slag powder content exceeds 50%, the alkali reserves are insufficient due to the reduction in clinker, the pH value of the hydration system decreases significantly, and the carbonation rate increases sharply. In addition, carbonation will also cause the cement stone structure formed by low-carbon slag powder cement to shrink in volume, aggravate the formation of cracks, and reduce impermeability and durability. In hydraulic structures, cement-based structures with a deep carbonization depth generally suffer from problems such as spalling and cracking, which seriously affect the service life of the building. Therefore, solving the carbonation problem of low-carbon slag powder cement is of great significance.

[0005] Currently, two main approaches are used to improve carbonation resistance: First, adding alkaline activators to increase alkalinity, but this carries the risk of alkali-aggregate reaction. Second, adding nanomaterials to refine the pore structure, but this is costly and prone to agglomeration and failure. Furthermore, these methods rely on energy-intensive raw materials or processes, leading to increased hidden carbon emissions and conflicting with low-carbon goals. Summary of the Invention

[0006] To this end, the present invention provides a carbonation-resistant low-carbon slag powder cement material and its application. This material neither triggers the risk of alkali-aggregate reaction nor relies on nanomaterials. It not only enhances the carbonation resistance of low-carbon slag powder cement but also helps improve the mechanical properties of low-carbon slag powder cement. Specifically, the technical solution of the present invention is as follows.

[0007] In a first aspect of the present invention, a carbonation-resistant low-carbon slag powder cement material is provided, comprising the following components in the following proportions: 55-75 parts by weight of slag powder, 15-25 parts by weight of gypsum powder, 3-10 parts by weight of a cementitious component, 1-3 parts by weight of spinel powder, and 2-5 parts by weight of an anti-carbonation agent. The anti-carbonation agent is composed of a mixture of polyferric sulfate, a water-soluble phosphate, and a water-soluble carbonate in a mass ratio of 7-10:3-5:1.

[0008] Furthermore, the components further include mixing water. Optionally, the ratio of the mixing water to the total mass of the slag powder, gypsum powder, and cementitious components is 0.35-0.6:1.

[0009] Furthermore, the components also include coarse and fine mixed aggregates, wherein the mass ratio of coarse aggregate to fine aggregate is 3.5 to 4: 1. Optionally, the mass ratio of the mixed aggregate to the total mass of the slag powder, gypsum powder, and cementitious components is 2 to 4: 1.

[0010] Furthermore, the components further include a water reducer. Optionally, the ratio of the water reducer to the total mass of the slag powder, gypsum powder, and cement gelling components is 0.0015-0.0045:1.

[0011] Furthermore, the water reducer includes at least one or more of polycarboxylic acid water reducer, naphthalene water reducer, melamine water reducer, etc.

[0012] Furthermore, the slag powder is graded to form powders with finenesses of 400-500 mesh, 500-600 mesh, 600-700 mesh, and 700-800 mesh. Optionally, the mass ratio of the 400-500 mesh, 500-600 mesh, 600-700 mesh, and 700-800 mesh powders is 10-20:55-65:10-23:7-10. This graded slag powder can exert a micro-aggregate effect, making the resulting cement paste structure denser, thereby improving its strength and durability.

[0013] Furthermore, the gypsum powder includes one or more of chemically pure gypsum powder, fluorgypsum powder, desulfurized gypsum powder, and phosphogypsum powder. Optionally, the gypsum powder has a fineness of 300-400 mesh. The gypsum powder acts as a sulfate activator, reacting with the active sulfate and calcium in the slag to form ettringite, which improves the early strength of the cement. Gypsum also neutralizes alkalinity in the system, promoting the formation of a more uniform microstructure.

[0014] Furthermore, the cement gelling component includes one or more of: Portland cement, benchmark cement, sulphoaluminate cement, high-belite sulphoaluminate cement, etc.

[0015] Furthermore, the water-soluble carbonate in the anti-carbonation agent includes one or more of sodium carbonate, potassium carbonate, ammonium carbonate, etc.

[0016] Furthermore, the water-soluble phosphate in the anti-carbonization agent includes one or more of sodium phosphate, potassium phosphate, etc.

[0017] In a second aspect of the present invention, there is provided the use of the carbonization-resistant low-carbon slag powder cement material in construction projects, bridge projects, road projects, airport runways, curbstones, crash barriers, carbon-fixing bricks, and the like.

[0018] Compared with the prior art, the present invention has at least the following beneficial technical effects: The carbonization-resistant low-carbon slag powder cement material of the present invention adopts an anti-carbonization agent formed by polyferric sulfate, calcium phosphate and water-soluble carbonate. It neither causes the risk of alkali-aggregate reaction nor relies on nanomaterials. It not only improves the carbonization resistance of low-carbon slag powder cement, but also helps to improve the mechanical properties of the low-carbon slag powder cement material after carbonization. This is because: first, the phosphate provided by the water-soluble phosphate reacts with the Ca generated by hydration in the cement pores. 2+ The formation of an amorphous calcium phosphate layer, which covers the surface of the cement hydration product, can effectively hinder the penetration and diffusion of CO2, thereby reducing the carbonization of calcium hydroxide in the cement stone structure into CaCO3, causing a series of problems such as reduced alkalinity. Second, the polyferric sulfate releases Fe in the alkaline environment provided by cement hydration. 3+ And quickly form Fe(OH)3 colloid, the large amount of positive charge carried on its surface and PO4 provided by the water-soluble phosphate and water-soluble carbonate 3- 、CO3 2- By forming a double electron layer through electrostatic attraction, it can effectively prevent the later external CO2 from entering the cement stone structure to form CO3 2- The migration and diffusion of ions can improve the carbonization resistance. 3+ Can also be used with PO4 3- Through FeSO4 (ferric sulfate under alkaline conditions, part of the iron ions undergo reduction reaction Fe 3+ +e - →Fe 2+ ) coordinate to form a framework, the water-soluble carbonate provides CO3 2- A gel layer with a three-dimensional network structure is formed in the skeleton, which can effectively prevent the infiltration of external CO2, thereby improving the carbonization resistance. The spinel powder (MgAl2O4) can supplement Al 3+ Promote the formation of CAH, which is more stable than CSH. In addition, Al in spinel 3+It will also react with the anti-carbonization agent to form aluminophosphate precipitate (Al 3+ +PO4 3- +2H2O→AlPO4·2H2O), its structure is more compact, which can not only reduce the entry of carbon dioxide and improve the carbonization resistance, but also help to improve the mechanical properties of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1 This is a sample picture of the anti-carbonization agent prepared in the following Example 1.

[0021] Figure 2 This is a compressive strength test diagram of the following Example 1.

[0022] Figure 3 This is a carbonization depth test diagram of the test piece prepared in the following Example 1 after carbonization.

[0023] Figure 4 This is a carbonization depth test diagram of the test piece prepared in the following Example 2 after carbonization.

[0024] Figure 5 This is a carbonization depth test diagram of the test piece prepared in the following Example 3 after carbonization.

[0025] Figure 6 This is a carbonization depth test diagram of the test piece prepared in the following Example 4 after carbonization.

[0026] Figure 7 This is a carbonization depth test diagram of the test piece prepared in the following Example 5 after carbonization.

[0027] Figure 8 This is a carbonization depth test diagram of the test piece prepared in the following Example 6 after carbonization.

[0028] Figure 9 This is a carbonization depth test diagram of the test piece prepared in the following Example 7 after carbonization. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. The experimental methods in the following examples, for which specific conditions are not specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0030] Unless otherwise defined, all professional and scientific terms used in the present invention have the same meanings as those familiar to those skilled in the art. The reagents and raw materials used in the present invention can be purchased through conventional channels. Unless otherwise specified, the reagents and raw materials used in the present invention are used in accordance with conventional methods in the art or in accordance with the product instructions.

[0031] In addition, any methods and materials similar or equivalent to those described herein can be applied to the method of the present invention. The technical solution of the present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0032] Example 1 A method for preparing a carbonization-resistant low-carbon slag powder cement material comprises the following steps: (1) Mix polyferric sulfate, sodium phosphate and sodium carbonate in a mass ratio of 8:5:1 to obtain Figure 1 Anti-carbonation agent as indicated, set aside.

[0033] (2) Weigh the raw materials according to the following proportions: 75 parts by weight of slag powder, 20 parts by weight of gypsum powder, 5 parts by weight of cement (PO42.5), 5 parts by weight of the anti-carbonization agent of this embodiment, 285 parts by weight of coarse and fine mixed aggregate, 2 parts by weight of spinel powder, and 46 parts by weight of mixing water. The mass ratio of the components (expressed in the form of oxides) in the slag powder is CaO:SiO2:Al2O3:MgO:Fe2O3:SO3:TiO2=34:30:18:7:0.3:2.5:1.5. The slag powder is graded from powders of 400 mesh, 500 mesh, 600 mesh, and 700 mesh in a mass ratio of 20:55:15:10. The gypsum powder is a mixture of anhydrous gypsum powder and dihydrate gypsum powder in a mass ratio of 1:2, with a fineness of 400 mesh, and the fineness of the spinel powder is 500 mesh. The mass ratio of crushed stone coarse aggregate (particle size 5-8 mm) to river sand fine aggregate (particle size 0.1-0.5 mm) in the coarse and fine mixed aggregate is 4:1.

[0034] (3) Add the anti-carbonization agent to the mixing water and stir evenly to obtain a mixed solution for use.

[0035] (4) The slag powder, gypsum powder, cement (PO 42.5), and spinel powder are mixed and stirred uniformly to obtain a ternary cementitious material. Then, the coarse and fine mixed aggregates are added and continued to be stirred to mix the raw materials uniformly. Finally, the mixed solution of step (3) is added and slowly stirred at a speed of 140 r / min for 120 s, stopped for 15 s, and then rapidly stirred at a speed of 600 r / min for 120 s to obtain a slag powder cement-based material.

[0036] The slag powder cement-based material prepared in this example was poured into a mold and then demolded. The mold was then placed in a curing box (curing temperature (20±2)°C, curing humidity 98%) for 28 days. The resulting specimens were then left to dry naturally for 48 hours. The specimens were then carbonized for 7 days and 14 days according to the "Test Method for Carbonization of Cement Mortar" (GB / T 42277-2022). The compressive strength of the specimens was then tested (e.g. Figure 2 as shown) and carbonization depth (as shown) Figure 3 The test results are shown in the following table: .

[0037] Example 2 A method for preparing a carbonization-resistant low-carbon slag powder cement material comprises the following steps: (1) Mix polyferric sulfate, sodium phosphate and sodium carbonate in a mass ratio of 10:4:1 to obtain an anti-carbonization agent for later use.

[0038] (2) Weigh the raw materials according to the following proportions: 70 parts by weight of slag powder, 15 parts by weight of 400-mesh desulfurized gypsum powder, 3 parts by weight of cement (PO 42.5), 2 parts by weight of the anti-carbonization agent of this embodiment, 176 parts by weight of coarse and fine mixed aggregate, 0.132 parts by weight of polycarboxylic acid water reducer, 3 parts by weight of spinel powder, and 30.8 parts by weight of mixing water. The mass ratio of the components (expressed in the form of oxides) in the slag powder is CaO:SiO2:Al2O3:MgO:Fe2O3:SO3:TiO2=34:30:18:7:0.3:2.5:1.5. The slag powder is graded from powders of 500-mesh, 600-mesh, 700-mesh, and 800-mesh finenesses in a mass ratio of 15:60:23:8. The gypsum powder is a mixture of anhydrous gypsum powder and dihydrate gypsum powder in a mass ratio of 1:2, with a fineness of 400 mesh. The spinel powder has a fineness of 500 mesh. The coarse and fine mixed aggregate has a mass ratio of crushed stone coarse aggregate (particle size 5-8mm) to river sand fine aggregate (particle size 0.1-0.5mm) of 4:1.

[0039] (3) Add the anti-carbonization agent to the mixing water and stir evenly to obtain a mixed solution for use.

[0040] (4) The slag powder, gypsum powder, cement (PO 42.5), spinel powder and water reducer are mixed and stirred uniformly to obtain a ternary cementitious material. Then, the coarse and fine mixed aggregates are added and continued to be stirred to mix the raw materials uniformly. Finally, the mixed solution of step (3) is added and slowly stirred at a speed of 140 r / min for 120 s, stopped for 15 s, and then quickly stirred at a speed of 600 r / min for 120 s to obtain a slag powder cement-based material.

[0041] The slag powder cement-based material prepared in this embodiment was poured into a mold and then demolded. The mold was then placed in a curing box (the curing temperature was set to (20±2)°C and the curing humidity was set to 98%) for 28 days. The resulting specimens were then left to dry naturally for 48 hours. The obtained specimens were then carbonized for 7 days and 14 days according to the "Test Method for Carbonization of Cement Mortar" (GB / T 42277-2022). The compressive strength and carbonization depth of the obtained specimens (such as Figure 4 The test results are shown in the following table: .

[0042] Example 3 A method for preparing a carbonization-resistant low-carbon slag powder cement material comprises the following steps: (1) Mix polyferric sulfate, potassium phosphate and potassium carbonate in a mass ratio of 7:3:1 to obtain an anti-carbonization agent for later use.

[0043] (2) Weigh the raw materials in the following proportions: 55 parts by weight of slag powder, 25 parts by weight of 300-mesh fluorgypsum powder, 10 parts by weight of cement (PO 42.5), 4 parts by weight of the anti-carbonization agent of this embodiment, 360 parts by weight of coarse and fine mixed aggregate, 0.405 parts by weight of naphthalene-based water reducer, 1 part by weight of spinel powder, and 54 parts by weight of mixing water. The mass ratio of the components (expressed in the form of oxides) in the slag powder is CaO:SiO2:Al2O3:MgO:Fe2O3:SO3:TiO2=34:30:18:7:0.3:2.5:1.5. The slag powder is graded from powders of 500-mesh, 600-mesh, 700-mesh, and 800-mesh finenesses in a mass ratio of 10:65:10:7. The mass ratio of crushed stone coarse aggregate (particle size 5-8 mm) to river sand fine aggregate (particle size 0.1-0.5 mm) in the coarse and fine mixed aggregate is 3.5:1.

[0044] (3) Add the anti-carbonization agent to the mixing water and stir evenly to obtain a mixed solution for use.

[0045] (4) The slag powder, gypsum powder, cement (PO 42.5), spinel powder and water reducer are mixed and stirred uniformly to obtain a ternary cementitious material. Then, the coarse and fine mixed aggregates are added and continued to be stirred to mix the raw materials uniformly. Finally, the mixed solution of step (3) is added and slowly stirred at a speed of 140 r / min for 120 s, stopped for 15 s, and then quickly stirred at a speed of 600 r / min for 120 s to obtain a slag powder cement-based material.

[0046] The slag powder cement-based material prepared in this embodiment was poured into a mold and then demolded. The mold was then placed in a curing box (curing temperature (20±2)°C, curing humidity 98%) for 28 days. The resulting specimens were then left to dry naturally for 48 hours. The specimens were then carbonized for 7 days and 14 days according to the "Test Method for Carbonization of Cement Mortar" (GB / T 42277-2022). The compressive strength and carbonization depth (such as Figure 5 The test results are shown in the following table: .

[0047] Example 4 A method for preparing a carbonization-resistant low-carbon slag powder cement material comprises the following steps: (1) Weigh the raw materials in the following proportions: 75 parts by weight of slag powder, 20 parts by weight of gypsum powder, 5 parts by weight of cement (PO42.5), 285 parts by weight of coarse and fine mixed aggregate, 2 parts by weight of spinel powder, and 46 parts by weight of mixing water. The mass ratio of the components (expressed in the form of oxides) in the slag powder is CaO:SiO2:Al2O3:MgO:Fe2O3:SO3:TiO2=34:30:18:7:0.3:2.5:1.5. The slag powder is graded from powders of 400 mesh, 500 mesh, 600 mesh, and 700 mesh in a mass ratio of 20:55:15:10. The gypsum powder is a mixture of anhydrous gypsum powder and dihydrate gypsum powder in a mass ratio of 1:2, with a fineness of 400 mesh, and the fineness of the spinel powder is 500 mesh. The mass ratio of crushed stone coarse aggregate (particle size 5-8 mm) to river sand fine aggregate (particle size 0.1-0.5 mm) in the coarse and fine mixed aggregate is 4:1.

[0048] (2) Add the anti-carbonization agent to the mixing water and stir evenly to obtain a mixed solution for use.

[0049] (3) The slag powder, gypsum powder, cement (PO 42.5), and spinel powder are mixed and stirred uniformly to obtain a ternary cementitious material. Then, the coarse and fine mixed aggregates are added and continued to be stirred to mix the raw materials uniformly. Finally, the mixed solution of step (2) is added and slowly stirred at a speed of 140 r / min for 120 s, stopped for 15 s, and then quickly stirred at a speed of 600 r / min for 120 s to obtain a slag powder cement-based material.

[0050] The slag powder cement-based material prepared in this embodiment was poured into a mold and then demolded. The mold was then placed in a curing box (curing temperature (20±2)°C, curing humidity 98%) for 28 days. The resulting specimens were then left to dry naturally for 48 hours. The specimens were then carbonized for 7 days and 14 days according to the "Test Method for Carbonization of Cement Mortar" (GB / T 42277-2022). The compressive strength and carbonization depth (such as Figure 6 The test results are shown in the following table: .

[0051] Example 5 A method for preparing a carbonization-resistant low-carbon slag powder cement material comprises the following steps: (1) Mix sodium phosphate and sodium carbonate in a mass ratio of 4:1 to obtain an anti-carbonation agent and set aside.

[0052] (2) Weigh the raw materials according to the following proportions: 70 parts by weight of slag powder, 15 parts by weight of 400-mesh desulfurized gypsum powder, 3 parts by weight of cement (PO 42.5), 2 parts by weight of the anti-carbonization agent of this embodiment, 176 parts by weight of coarse and fine mixed aggregate, 0.132 parts by weight of polycarboxylic acid water reducer, 3 parts by weight of spinel powder, and 30.8 parts by weight of mixing water. The mass ratio of the components (expressed in the form of oxides) in the slag powder is CaO:SiO2:Al2O3:MgO:Fe2O3:SO3:TiO2=34:30:18:7:0.3:2.5:1.5. The slag powder is graded from powders of 500-mesh, 600-mesh, 700-mesh, and 800-mesh finenesses in a mass ratio of 15:60:23:8. The gypsum powder is a mixture of anhydrous gypsum powder and dihydrate gypsum powder in a mass ratio of 1:2, with a fineness of 400 mesh. The spinel powder has a fineness of 500 mesh. The coarse and fine mixed aggregate has a mass ratio of crushed stone coarse aggregate (particle size 5-8mm) to river sand fine aggregate (particle size 0.1-0.5mm) of 4:1.

[0053] (3) Add the anti-carbonization agent to the mixing water and stir evenly to obtain a mixed solution for use.

[0054] (4) The slag powder, gypsum powder, cement (PO 42.5), spinel powder and water reducer are mixed and stirred uniformly to obtain a ternary cementitious material. Then, the coarse and fine mixed aggregates are added and continued to be stirred to mix the raw materials uniformly. Finally, the mixed solution of step (3) is added and slowly stirred at a speed of 140 r / min for 120 s, stopped for 15 s, and then quickly stirred at a speed of 600 r / min for 120 s to obtain a slag powder cement-based material.

[0055] The slag powder cement-based material prepared in this embodiment was poured into a mold and then demolded. The mold was then placed in a curing box (curing temperature (20±2)°C, curing humidity 98%) for 28 days. The resulting specimens were then left to dry naturally for 48 hours. The specimens were then carbonized for 7 days and 14 days according to the "Test Method for Carbonization of Cement Mortar" (GB / T 42277-2022). The compressive strength and carbonization depth (such as Figure 7 The test results are shown in the following table: .

[0056] Example 6 A method for preparing a carbonization-resistant low-carbon slag powder cement material comprises the following steps: (1) Mix polyferric sulfate and potassium carbonate in a mass ratio of 7:1 to obtain an anti-carbonization agent for later use.

[0057] (2) Weigh the raw materials according to the following proportions: 55 parts by weight of slag powder, 25 parts by weight of 300-mesh fluorgypsum powder, 10 parts by weight of cement (PO 42.5), 4 parts by weight of the anti-carbonization agent of this embodiment, 360 parts by weight of coarse and fine mixed aggregate, 0.405 parts by weight of naphthalene-based water reducer, 1 part by weight of spinel powder, and 54 parts by weight of mixing water. The mass ratio of the components (expressed in the form of oxides) in the slag powder is CaO:SiO2:Al2O3:MgO:Fe2O3:SO3:TiO2=34:30:18:7:0.3:2.5:1.5. The slag powder is graded from powders of 500-mesh, 600-mesh, 700-mesh, and 800-mesh finenesses in a mass ratio of 10:65:10:7. The spinel powder has a fineness of 500-mesh. The mass ratio of crushed stone coarse aggregate (particle size 5-8 mm) to river sand fine aggregate (particle size 0.1-0.5 mm) in the coarse and fine mixed aggregate is 3.5:1.

[0058] (3) Add the anti-carbonization agent to the mixing water and stir evenly to obtain a mixed solution for use.

[0059] (4) The slag powder, gypsum powder, cement (PO 42.5), spinel powder and water reducer are mixed and stirred uniformly to obtain a ternary cementitious material. Then, the coarse and fine mixed aggregates are added and continued to be stirred to mix the raw materials uniformly. Finally, the mixed solution of step (3) is added and slowly stirred at a speed of 140 r / min for 120 s, stopped for 15 s, and then quickly stirred at a speed of 600 r / min for 120 s to obtain a slag powder cement-based material.

[0060] The slag powder cement-based material prepared in this embodiment was poured into a mold and then demolded. The mold was then placed in a curing box (curing temperature (20±2)°C, curing humidity 98%) for 28 days. The resulting specimens were then left to dry naturally for 48 hours. The specimens were then carbonized for 7 days and 14 days according to the "Test Method for Carbonization of Cement Mortar" (GB / T 42277-2022). The compressive strength and carbonization depth (such as Figure 8 The test results are shown in the following table: .

[0061] Example 7 A method for preparing a carbonization-resistant low-carbon slag powder cement material comprises the following steps: (1) Mix polyferric sulfate and sodium phosphate in a mass ratio of 8:5 to obtain an anti-carbonization agent for later use.

[0062] (2) Weigh the raw materials according to the following proportions: 75 parts by weight of slag powder, 20 parts by weight of gypsum powder, 5 parts by weight of cement (PO42.5), 5 parts by weight of the anti-carbonization agent of this embodiment, 285 parts by weight of coarse and fine mixed aggregate, 1 part by weight of spinel powder, and 46 parts by weight of mixing water. The mass ratio of the components (expressed in the form of oxides) in the slag powder is CaO:SiO2:Al2O3:MgO:Fe2O3:SO3:TiO2=34:30:18:7:0.3:2.5:1.5. The slag powder is graded from powders of 400 mesh, 500 mesh, 600 mesh, and 700 mesh in a mass ratio of 20:55:15:10. The gypsum powder is a mixture of anhydrous gypsum powder and dihydrate gypsum powder in a mass ratio of 1:2, with a fineness of 400 mesh, and the fineness of the spinel powder is 500 mesh. The mass ratio of crushed stone coarse aggregate (particle size 5-8 mm) to river sand fine aggregate (particle size 0.1-0.5 mm) in the coarse and fine mixed aggregate is 4:1.

[0063] (3) Add the anti-carbonization agent to the mixing water and stir evenly to obtain a mixed solution for use.

[0064] (4) The slag powder, gypsum powder, cement (PO 42.5), and spinel powder are mixed and stirred uniformly to obtain a ternary cementitious material. Then, the coarse and fine mixed aggregates are added and continued to be stirred to mix the raw materials uniformly. Finally, the mixed solution of step (3) is added and slowly stirred at a speed of 140 r / min for 120 s, stopped for 15 s, and then rapidly stirred at a speed of 600 r / min for 120 s to obtain a slag powder cement-based material.

[0065] The slag powder cement-based material prepared in this embodiment was poured into a mold and then demolded. The mold was then placed in a curing box (curing temperature (20±2)°C, curing humidity 98%) for 28 days. The resulting specimens were then left to dry naturally for 48 hours. The specimens were then carbonized for 7 days and 14 days according to the "Test Method for Carbonization of Cement Mortar" (GB / T 42277-2022). The compressive strength and carbonization depth (such as Figure 9 The test results are shown in the following table: .

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A carbonization-resistant low-carbon slag powder cement material, characterized in that: The invention comprises the following components in the following proportions: 55-75 parts by weight of slag powder, 15-25 parts by weight of gypsum powder, 3-10 parts by weight of cement gelling component, 1-3 parts by weight of spinel powder, and 2-5 parts by weight of an anti-carbonation agent; wherein the anti-carbonation agent is composed of a mixture of polyferric sulfate, water-soluble phosphate, and water-soluble carbonate in a mass ratio of 7-10:3-5:

1.

2. The carbonization-resistant low-carbon slag powder cement material according to claim 1, characterized in that: The components also include mixing water; optionally, the ratio of the mixing water to the total mass of the slag powder, gypsum powder and cement gelling components is 0.35~0.6:

1.

3. The carbonization-resistant low-carbon slag powder cement material according to claim 1, characterized in that: The components also include coarse and fine mixed aggregates, wherein the mass ratio of coarse aggregate to fine aggregate is 3.5-4:1; optionally, the mass ratio of the mixed aggregate to the total mass of the slag powder, gypsum powder and cement gelling components is 2-4:

1.

4. The carbonization-resistant low-carbon slag powder cement material according to claim 1, characterized in that: The components also include a water reducer; optionally, the ratio of the water reducer to the total mass of the slag powder, gypsum powder and cement gelling components is 0.0015~0.0045:

1.

5. The carbonization-resistant low-carbon slag powder cement material according to claim 4, characterized in that: The water reducer includes at least one or more of a polycarboxylic acid water reducer, a naphthalene water reducer, and a melamine water reducer.

6. The carbonization-resistant low-carbon slag powder cement material according to claim 1, characterized in that: The slag powder is graded from powders with finenesses of 400-500 mesh, 500-600 mesh, 600-700 mesh, and 700-800 mesh.

7. The carbonization-resistant low-carbon slag powder cement material according to claim 6, characterized in that: The mass ratio of the powders of 400-500 mesh, 500-600 mesh, 600-700 mesh, and 700-800 mesh is 10-20:55-65:10-23:7-10.

8. The carbonization-resistant low-carbon slag powder cement material according to any one of claims 1 to 7, characterized in that: The gypsum powder includes: one or more of chemically pure gypsum powder, fluorgypsum powder, desulfurized gypsum powder, and phosphogypsum powder; optionally, the fineness of the gypsum powder is 300-400 mesh.

9. The carbonization-resistant low-carbon slag powder cement material according to any one of claims 1 to 7, characterized in that: The cement gelling component includes: one or more of Portland cement, standard cement, sulphoaluminate cement, and high-belite sulphoaluminate cement; Optionally, the water-soluble carbonate in the anti-carbonation agent includes one or more of sodium carbonate, potassium carbonate, and ammonium carbonate; Optionally, the water-soluble phosphate in the anti-carbonization agent includes one or more of sodium phosphate and potassium phosphate.

10. Use of the carbonization-resistant low-carbon slag powder cement material according to any one of claims 1 to 9 in at least one of construction projects, bridge projects, road projects, airport runways, curbstones, crash barriers, and carbon-fixing bricks.

Images