Homogeneous carbonized cementing material based on chemical controlled release of solid carbon source and application of homogeneous carbonized cementing material

Abstract

The invention relates to a homogeneous carbonized cementing material based on solid carbon source chemical controlled release and application thereof.The homogeneous carbonized cementing material is prepared from, by mass, 70-98 parts of a base material to be carbonized and activated, 2-30 parts of an endogenous solid carbon releasing agent, 1-45 parts of an endogenous release triggering agent and 21-77 parts of water; the endogenous solid carbon releasing agent comprises one or more of natural calcium minerals and carbonized and regenerated calcium-containing solid wastes; the endogenous release trigger includes one or more of an aluminate of an alkali metal and a hydroxide of an alkali metal. Under the triggering of the endogenous release triggering agent, the non-gaseous carbon source is released in situ in the system, the homogeneous and synchronous hardening from the core to the surface layer is realized, the homogeneity of the final hardened body is ensured, and the compressive strength of the product is high.

Description

Technical Field

[0001] This invention relates to the field of carbonized cementitious materials, specifically to a homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source and its applications. Background Technology

[0002] Industrial byproducts such as steel slag and magnesium slag, which are rich in highly reactive calcium-magnesium silicate minerals (e.g., β-C2S, γ-C2S), are core raw materials for constructing sustainable building materials systems. However, these materials generally suffer from low early-stage reactivity and insufficient hardened body strength.

[0003] The current mainstream modification technology is "external gas infiltration strengthening," which involves curing and pressing the preform in an environment rich in CO2 gas. The drawback of this method is that the diffusion rate of CO2 from the surface to the interior is uneven, easily forming a dense mineralized hard shell on the surface of the product, i.e., a "reaction shell," which hinders further gas penetration. This results in a significant difference in the degree of transformation between the inside and outside of the product, with no significant improvement in the properties of the internal substrate, and uneven overall mechanical properties. Furthermore, this effect becomes increasingly pronounced as the component size increases, limiting its application to small, thin-walled products.

[0004] To overcome size limitations, the academic community proposed the "internal reaction" approach, which mainly involves mixing pre-adsorbed CO2 porous media into the substrate. However, the fundamental drawback of this technology is that the physical adsorption binding force of carbon dioxide is weak and its capacity is low. During construction processes such as stirring and vibration, a large number of gas molecules will desorb and be lost prematurely, resulting in the actual amount of material participating in the reaction being far less than the design value, leading to unsatisfactory conversion effects and stability.

[0005] Meanwhile, another technical approach explores the reaction of natural calcareous minerals (such as limestone powder) with added aluminate cement to generate hydrated carboaluminate as the main binder phase. The core of this technical approach lies in the hydration of aluminate, rather than the mineralization modification of silicate substrates, and it fails to solve the fundamental problem of activating the activity and improving the overall performance of calcium-rich silicate solid waste (such as steel slag).

[0006] In summary, how to develop a novel technical approach that does not rely on external gas diffusion, is not constrained by component size, and has stable and efficient internal reactants to achieve overall and homogeneous strengthening of the target substrate is a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a homogeneous carbonized cementitious material based on the chemical controlled release of solid carbon source and its application, solving the technical problems in the prior art where the reinforcement of the green body through external gas permeation is limited by the "reaction shell" and component size, and the physical adsorption internal reaction has low efficiency and instability.

[0008] To achieve the above-mentioned technical objectives, the technical solution provided by this invention is as follows: In a first aspect, the present invention provides a homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source, comprising the following raw materials by mass: a substrate to be carbonized and activated: 70-98 parts; an endogenous solid carbon release agent: 2-30 parts; an endogenous release trigger agent: 1-45 parts; and water: 21-77 parts. The endogenous solid carbon release agent includes one or more of natural calcareous minerals and carbonized recycled calcium-containing solid waste. The endogenous release trigger agent includes one or more of alkali metal aluminates and alkali metal hydroxides.

[0009] Secondly, the present invention provides an application of the above-mentioned homogeneous carbonization cementitious material based on the chemical controlled release of solid carbon source in the preparation of a homogeneous hardened body, comprising the following steps: S1, mixing an endogenous release trigger agent and water to prepare an activation solution; dry mixing the substrate to be carbonized and activated with an endogenous solid carbon release agent to obtain a uniformly dispersed mixed powder; S2, mixing the activation solution with the mixed powder and stirring evenly to obtain a mixture; S3, casting the mixture into a mold and sealing it for curing to obtain a homogeneous hardened body.

[0010] Compared with the prior art, the beneficial effects of the present invention include: This invention utilizes an endogenous solid carbon-releasing agent as a latent, non-gaseous carbon-containing reactant. Under the triggering action of an endogenous release trigger, it enables the in-situ, uniform release of active CO3 within the mixture. 2- These ions then interact with the surrounding target substrate to complete the overall hardening process. This invention, through a conversion pathway driven by internal chemical action and releasing non-gaseous carbon sources in situ within the system, achieves homogeneous and synchronous hardening from the core to the surface, ensuring the homogeneity of the final hardened body. Due to the stability and sufficient action of the internal reactants, the product of this invention has high compressive strength. At the same time, by avoiding the generation of unstable hydration products, the long-term volume stability and strength of the material are guaranteed. Furthermore, by controlling the amount of each component, the triggering efficiency is ensured while improving the operability of construction. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0012] To address the shortcomings of existing technologies, such as the limitations of external gas permeation reinforcement of the preform due to the "reaction shell" and component size, and the low efficiency and instability of physical adsorption internal reactions, this invention provides a homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source and its application. It is a novel chemically driven internal homogeneous conversion method that ensures that the conversion process can occur synchronously and homogeneously at any location within the system through a two-stage synergistic mechanism of "endogenous release-in-situ reaction," thereby producing a homogeneous high-performance hardened body that is not limited by size.

[0013] The homogeneous carbonized cementitious material of this invention is a composite material composition consisting of multiple components capable of internal homogeneous transformation. Its core technology lies in the presence of a latent, non-gaseous carbonaceous reactant within the system. This substance, triggered by a specific chemical reagent, can release reactive CO3 in situ and uniformly within the mixture. 2- These ions then interact with the surrounding target substrate, completing the overall hardening process.

[0014] In a first aspect, the present invention provides a homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source, comprising, by mass parts: (A) a substrate to be activated by carbonization: 70-98 parts; (B) an endogenous solid carbon release agent: 2-30 parts; (C) an endogenous release trigger agent: 1-45 parts; and (D) water: 21-77 parts. The endogenous solid carbon release agent includes one or more of natural calcareous minerals and carbonized recycled calcium-containing solid waste. The endogenous release trigger agent includes one or more of alkali metal aluminates and alkali metal hydroxides.

[0015] In this invention, the ratio of component C to component B is the chemical core, mainly determining the efficiency and extent of the reaction; the ratio of component A to component B is the materials science core, mainly determining the balance between the substrate and the filler; component D is the physical core, determining the water-binder ratio, which affects the density and strength of the final product.

[0016] Preferably, the substrate to be carbonized and activated includes one or more of steel slag and magnesium slag.

[0017] The substrate to be carbonized and activated in this invention is rich in CO3. 2- The powder material of calcium or magnesium silicate mineral phases (such as γ-C2S, β-C2S, etc.) that undergo chemical reaction is mainly derived from industrial solid wastes such as steel slag and magnesium slag. This component is the main body that is mineralized and modified to achieve performance improvement in this invention.

[0018] Preferably, the specific surface area of ​​the substrate to be carbonized and activated is 300–600 m². 2 / kg, with a particle size of 10–75 μm.

[0019] The carbonized and activated substrate of this invention needs to be ground before use in order to control its specific surface area and particle size, which is beneficial to improving product performance.

[0020] Preferably, the natural calcium minerals include limestone powder; the carbonized recycled calcium-containing solid waste includes one or more of carbonized recycled concrete powder and carbonized carbide slag.

[0021] In this invention, the endogenous solid carbon release agent refers to a chemically stable substance that can decompose and release CO3 under specific conditions. 2- The powdery substance. Its source can be natural calcareous minerals (such as limestone powder), but its preferred source is pretreated calcium-containing solid waste, such as carbonized recycled concrete fine powder and carbonized carbide slag. Choosing the latter as the preferred source has the following significant technical advantages: 1) Dual carbon fixation and recycling value: When preparing this component, the calcium-containing solid waste is pretreated using waste CO2 from industrial flue gas, which itself completes a CO2 capture and solid waste resource utilization. Compared with the direct mining of natural resources, its environmental benefits and social value are huge; 2) Higher reactivity: CaCO3 generated by artificial carbonization process usually has a higher specific surface area and / or metastable crystal form than natural minerals after grinding. This is conducive to its faster and more complete release of active anions under the action of triggering agents, thereby improving the reaction efficiency of the entire system; 3) Potential synergistic enhancement effect: Taking carbonized recycled concrete fine powder as an example, the small amount of residual hydration products (such as CSH gel) it contains can act as crystal nuclei in the system, promote the generation of new products, and play a positive synergistic role in the optimization of the final microstructure and the improvement of strength. This component is the "carbon pool" within the system, providing a source of materials for the in-situ conversion process.

[0022] Preferably, the carbonized regeneration of calcium-containing solid waste is obtained by crushing and grinding calcium-containing solid waste, followed by carbonization and drying. The carbonization conditions include: CO2 concentration of 15% to 100%, relative humidity of 50% to 80%, temperature of 20 to 80°C, and time of 6 to 24 hours.

[0023] The present invention mainly involves carbonizing and regenerating calcium-containing solid waste by crushing the calcium-containing solid waste and then placing it in a specific CO2 atmosphere (such as industrial flue gas) for carbonization treatment until the active calcium (such as calcium hydroxide) in the calcium-containing waste is fully converted into calcium carbonate, and the carbon dioxide is stabilized and solidified in the form of chemical bonds. This carbonization treatment is the key to ensuring that component (B) can serve as an effective "carbon pool". If this step is omitted and calcium-containing waste that has not been carbonized is used directly, there will be no stable carbon source that can be chemically released in a controlled manner in the system, and the core technical path of the present invention will not be realized, resulting in a significant decrease in the performance of the final product.

[0024] Preferably, the alkali metal aluminate includes at least one of NaAlO2 and potassium aluminate; the alkali metal hydroxide includes at least one of sodium hydroxide and potassium hydroxide.

[0025] In this invention, the endogenous release trigger is a chemical auxiliary that can chemically react with component (B), break its stable structure, and promote the release of active anions. It is understood that the endogenous release trigger can be an aqueous solution of an alkali metal aluminate, an alkali metal hydroxide, or any combination thereof. When calculating the amount of components in this invention, the amount is based on the solid content of the endogenous release trigger.

[0026] More preferably, the endogenous release trigger is NaAlO2.

[0027] Preferably, the mass ratio of the amount of endogenous release trigger to the mass of endogenous solid carbon release agent is (0.4-1.5):1, and more preferably (0.6-0.8):1.

[0028] Preferably, the ratio of the mass of water to the total mass of the substrate to be carbonized and activated and the endogenous solid carbon release agent, i.e., the water-binder ratio, is 0.3 to 0.6, and more preferably 0.4 to 0.5.

[0029] Preferably, by weight, the following raw materials are included: (A) substrate to be carbonized and activated: 80-95 parts, (B) endogenous solid carbon release agent: 5-20 parts, (C) endogenous release trigger agent: 3-16 parts, (D) water: 34-58 parts.

[0030] Secondly, the present invention provides an application of the above-mentioned homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source in the preparation of a homogeneous hardened body, comprising the following steps: S1, an activation solution is prepared by mixing an endogenous release trigger agent with water; the substrate to be carbonized and activated (component A) is dry-mixed with an endogenous solid carbon release agent (component B) to obtain a uniformly dispersed mixed powder. S2, mix the activation solution with the mixed powder, stir evenly to obtain the mixture; S3, the mixture is poured into a mold and sealed for curing to obtain a homogeneous hardened body.

[0031] Preferably, in step S1, the mass concentration of the activation solution is 10-50%.

[0032] The activation solution of this invention preferably uses sodium aluminate solution, which, as a reaction initiator, has dual functional advantages: firstly, it can provide a strongly alkaline environment (OH-). - Firstly, it effectively disrupts the stable structure of component (B), which is a prerequisite for initiating endogenous release; secondly, it can provide unique aluminate ions ([Al(OH)4]). -This ion can directly participate in subsequent secondary reactions to generate products such as calcium aluminate monocarbonate, which has excellent mechanical properties. This significantly enhances the final strength, a capability not possessed by a single alkaline substance (such as sodium hydroxide). The mass concentration of the activation solution is 10–50%, and this concentration range is equally crucial: below 10%, the ion concentration is insufficient, resulting in low triggering efficiency and an inability to effectively initiate endogenous release; above 50%, the reaction is too vigorous, easily leading to "instantaneous solidification" and rendering the material unusable for construction. This component is the "switch" that initiates the entire internal transformation process.

[0033] Preferably, in step S2, the stirring time is 1 to 3 minutes.

[0034] This invention involves adding an activation solution to a mixed powder and rapidly stirring for 1-3 minutes. During this process, the endogenous release trigger quickly acts on the endogenous solid carbon release agent, causing CO3 to be uniformly released from the mixture. 2- .

[0035] In the molding and curing process of this invention, the uniformly stirred fluid mixture is poured into shape. Since the internal chemical reaction occurs spontaneously, no external CO2 supply or pressurized heating is required. Only conventional sealing curing at room temperature is needed.

[0036] This invention is a "second-order chemical reaction" process, and the main reaction mechanism includes: First-order reaction (endogenous release): The high alkalinity and specific ionic environment provided by the activation solution rapidly react with CaCO3 in the endogenous solid carbon releasing agent, disrupting its crystal lattice, thereby uniformly releasing a high concentration of active anions (CO3-) throughout the liquid phase. 2- ).

[0037] Secondary reaction (in-situ mineralization): CO3 released from the primary reaction 2- As a reactant, it immediately undergoes in-situ mineralization with the calcium silicate minerals dispersed on the surface of the substrate to be carbonized and activated (such as steel slag particles) in the system. This process generates a dense composite product layer composed of nascent calcareous minerals and amorphous silica gel, which encapsulates and binds the substrate particles to form a high-strength microstructure.

[0038] The main advantages of this invention are: (1) Overcoming size limitations and achieving homogeneous strengthening: This invention fundamentally solves the problems of "reaction shell" and "uniform internal and external properties" caused by external gas permeation strengthening relying on diffusion processes through a transformation path driven by internal chemical action. Regardless of the size or complexity of the component, homogeneous and synchronous hardening from the core to the surface can be achieved; (2) Significant and stable performance improvement: Due to the stability and full action of the internal reactants, the 28-day compressive strength of the product of this invention can be increased by more than 5 times compared with traditional water curing. At the same time, the long-term volume stability and strength of the material are guaranteed by avoiding the formation of unstable hydration products; (3) Dual carbon sequestration with outstanding environmental benefits: This invention includes two carbon dioxide capture processes: First, in the preparation of the "endogenous solid carbon release agent", industrial flue gas and other materials are used to pretreat calcium-containing solid waste to achieve the first CO2 capture; Second, in the final product, carbon dioxide is permanently sealed in the form of stable calcium minerals, and the technical path is green and environmentally friendly. (4) The process is greatly simplified and the applicability is wide: This invention does not require complex equipment such as high-pressure reactors. The preparation process can be completed at normal temperature and pressure. It has low energy consumption and is easy to operate. It can be directly applied to various scenarios such as precast component production, 3D printing buildings, on-site casting and repair and reinforcement.

[0039] This invention releases a non-gaseous carbon source in situ within the system via a chemical pathway to achieve overall homogeneous strengthening of the target substrate. The entire process is driven by liquid-phase ion action and does not rely on gas diffusion. Therefore, it can occur simultaneously at any location within the material, ensuring the homogeneity of the final hardened body.

[0040] The present invention will be further described in detail below through specific embodiments. To avoid redundancy, some raw materials will be uniformly described here: (A) Substrate to be carbonized and activated: Steel slag powder from a steel plant was selected, with a specific surface area of ​​approximately 450 m² / kg; (B) Intrinsic solid carbon release agent: Carbonized recycled concrete fine powder is selected. The carbonization conditions include: CO2 concentration of 20%, relative humidity of 75%, temperature of 25℃, and time of 8 hours. (C) Endogenous release trigger: analytical grade NaAlO2 was used.

[0041] Example 1 The application of a homogeneous carbonized cementitious material based on the chemically controlled release of a solid carbon source in the preparation of homogeneous hardened bodies includes the following steps: S1, 13.3g of endogenous release trigger (component C, NaAlO2 solid) and 45g of water are mixed to prepare an activation solution; 80g of the substrate to be carbonized and activated (component A) and 20g of endogenous solid carbon release agent (component B) are dry-mixed to obtain a uniformly dispersed mixed powder. S2, mix the activation solution with the mixed powder, stir at high speed for 120 seconds to mix evenly, and obtain a mixture; at this time, the C:B mass ratio is 0.67:1, and the water-binder ratio is 0.45; S3. The mixture is poured into 20mm cube specimens and sealed for curing to obtain homogeneous hardened specimens.

[0042] The compressive strength and setting time of the obtained specimens were tested, and the results are shown in Table 1 below.

[0043] Table 1. Compressive strength and setting time of the specimens obtained in Example 1

[0044] Example 2 (Reducing the C:B ratio) Compared with Example 1, the only difference is that the amount of NaAlO2 solid is adjusted to 8g, and the other steps and conditions are the same as in Example 1 (at this time, the C:B mass ratio is 0.4:1); the other steps and conditions are the same as in Example 1.

[0045] The test results showed that the 28-day compressive strength of the specimen was 18.2 MPa and the final setting time was 75 min.

[0046] Example 3 (Improving the C:B ratio) Compared with Example 1, the only difference is that the amount of NaAlO2 solid is adjusted to 24g (at which point the C:B mass ratio is 1.2:1); the other steps and conditions are the same as in Example 1.

[0047] The test results showed that the 28-day compressive strength of the obtained specimen was 24.5 MPa; however, the mixture had poor fluidity and exhibited a "quick-setting" phenomenon (initial setting <3 min), making it difficult to form, and there were obvious pore defects inside the specimen.

[0048] Example 4 (reducing the A:B ratio, i.e., increasing the B content) Compared with Example 1, the only difference is that the amount of the substrate to be carbonized and activated (component A) is adjusted to 70g, the amount of the endogenous solid carbon release agent (component B) is adjusted to 30g, and the C:B mass ratio is maintained at 0.67:1 (i.e., NaAlO2 is adjusted to 20g), and the water-binder ratio is maintained at 0.45 (i.e., water 45g); other steps and conditions are the same as in Example 1.

[0049] The test results showed that the 28-day compressive strength of the specimen was 25.1 MPa and the final setting time was 40 min.

[0050] Example 5 (Increasing the A:B ratio, i.e., reducing the amount of B doping) Compared with Example 1, the only difference is that the amount of component A is adjusted to 95g, the amount of component B is adjusted to 5g, and the mass ratio of C:B is maintained at 0.67:1 (i.e., NaAlO2 is adjusted to 3.35g), and the water-cement ratio is 0.45; other steps and conditions are the same as in Example 1.

[0051] The test results showed that the 28-day compressive strength of the specimen was 26.8 MPa.

[0052] Example 6 (Increasing the water-cement ratio) Compared with Example 1, the only difference is that the amount of water is adjusted to 60g (the water-to-gel ratio is 0.60), while the amounts of other raw materials are the same as in Example 1.

[0053] The test results showed that the 28-day compressive strength of the specimen was 15.5 MPa and the final setting time was 95 min.

[0054] Example 7 (Reducing the water-cement ratio) Compared with Example 1, the only difference is that the amount of water is adjusted to 35g (at which point the water-gel ratio is 0.35); the other steps and conditions are the same as in Example 1.

[0055] The test results showed that the 28-day compressive strength of the obtained specimens was 36.5 MPa (if the molding was dense); however, the mixture was very dry and difficult to self-level, requiring strong vibration to form, resulting in poor workability.

[0056] Comparative Example 1 (Component C - Endogenous Release Trigger Solution Concentration Too Low) Compared to Example 1, the only difference is that 4.66g of NaAlO2 was dissolved in 45g of water to prepare a low-concentration activation solution (approximately 9.4%), which was then added to 100g of mixed powder (80g A + 20g B). This example maintains a water-cement ratio of 0.45, but significantly reduces the concentration and total amount of the trigger (the C:B ratio is reduced to 0.23:1). All other steps and conditions are the same as in Example 1.

[0057] The test results showed that the 28-day compressive strength of the specimen was only 5.2 MPa, and the final setting time was extended to 210 min, indicating that the reaction is difficult to start effectively at low concentrations.

[0058] Comparative Example 2 (Single Basic Trigger) The only difference from Example 1 is that equimolar amounts of OH are used. - Sodium hydroxide (NaOH, about 6.5g) was used instead of NaAlO2 as the endogenous release trigger, and the other steps and conditions were the same as in Example 1.

[0059] The test results showed that the 28-day compressive strength of the specimen was only 19.5 MPa.

[0060] Comparative Example 3 (No preprocessing) Compared with Example 1, the only difference is that component B uses recycled concrete powder that has not undergone carbonation pretreatment, while the other steps and conditions are the same as in Example 1.

[0061] The test results showed that the 28-day compressive strength of the specimen was 17.5 MPa and the final setting time was 81 min.

[0062] As shown in Examples 1-3, the ratio (C:B) of the endogenous release trigger to the endogenous solid carbon release agent is the key to determining the reaction efficiency. If the C:B ratio is too low, it will not affect the compressive strength and final setting time of the hardened specimen. This is mainly because insufficient amount of endogenous release trigger leads to insufficient carbon release, which fails to fully activate the carbon source and results in a low degree of mineralization reaction, thus affecting the strength. On the other hand, if the C:B ratio is too high, it will affect the fluidity of the mixture and the initial setting time. In this invention, the C:B ratio (the mass ratio of the amount of endogenous release trigger to the mass of the endogenous solid carbon release agent) can be selected as (0.4-1.5):1, and is further preferred as (0.6-0.8):1. The "endogenous release-in-situ reaction" system introduced in this invention can greatly accelerate the hardening process and significantly improve the final strength of the material.

[0063] Comparing Examples 1 (optimal ratio) and Examples 4-5, it can be seen that there is a balance point in the ratio (A:B) of the main carbonized and activated substrate to the endogenous solid carbon release agent. For example, in Example 4, the content of the carbonized and activated substrate (component A) that serves as the main skeleton is reduced, and the total strength of the system is affected, which is lower than the optimal ratio in Example 1. Similarly, the compressive strength in Example 5 is also lower than that in Example 1. Therefore, it is necessary to ensure the content of the main skeleton material in order to obtain the optimal strength (Examples 1, 4-5).

[0064] As can be seen from the comparison of Example 1 (optimal ratio) and Examples 6-7, the water-cement ratio (D) is the basis for determining the density and strength of the final hardened body. If it is too high, the performance will be seriously degraded. Therefore, the water-cement ratio of the present invention can be selected from 0.3 to 0.6. In order to balance strength and workability, it is further preferred to be 0.4 to 0.5.

[0065] As can be seen from the comparison between Example 1 and Comparative Example 1, the concentration of the endogenous release trigger solution must be within a suitable range; if it is too low, the reaction cannot be effectively initiated (Comparative Example 1).

[0066] As can be seen from the comparison between Example 1 and Comparative Example 2, the type of endogenous release trigger is crucial, and the dual function of sodium aluminate (basic + aluminate) has an unparalleled advantage over a single basic substance (Comparative Example 2).

[0067] Finally, by comparing Example 1 and Comparative Example 3, the necessity of carbonation treatment is clearly revealed. When recycled concrete fine powder without carbonation pretreatment is used directly, the system cannot form an effective "endogenous solid carbon release agent," causing the core "chemical controlled release" mechanism of this invention to fail, and the final strength is only 17.5 MPa, far lower than 32 MPa in Example 1. This proves that the pretreatment step is an indispensable prerequisite for achieving the excellent performance of this invention.

[0068] In summary, the above embodiments collectively verify that there is a close synergistic relationship between the components and their proportions proposed in this invention.

[0069] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source, characterized in that, By weight, it includes the following raw materials: substrate to be carbonized and activated: 70-98 parts, endogenous solid carbon release agent: 2-30 parts, endogenous release trigger agent: 1-45 parts, water: 21-77 parts. The endogenous solid carbon release agent includes one or more of natural calcium minerals and carbonized recycled calcium-containing solid waste. The endogenous release trigger includes one or more of alkali metal aluminates and alkali metal hydroxides.

2. The homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source according to claim 1, characterized in that, The substrate to be carbonized and activated includes one or more of steel slag and magnesium slag.

3. The homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source according to claim 1, characterized in that, The specific surface area of ​​the substrate to be carbonized and activated is 300–600 m². 2 / kg, with a particle size of 10–75 μm.

4. The homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source according to claim 1, characterized in that, The natural calcium minerals include limestone powder; the carbonized recycled calcium-containing solid waste includes one or more of carbonized recycled concrete powder and carbonized carbide slag.

5. The homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source according to claim 4, characterized in that, The carbonized recycled calcium-containing solid waste is obtained by crushing and grinding calcium-containing solid waste, followed by carbonization and drying. The carbonization treatment conditions include: CO2 concentration of 15% to 100%, relative humidity of 50% to 80%, temperature of 20 to 80°C, and time of 6 to 24 hours.

6. The homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source according to claim 1, characterized in that, The alkali metal aluminate includes at least one of NaAlO2 and potassium aluminate; the alkali metal hydroxide includes at least one of sodium hydroxide and potassium hydroxide.

7. The homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source according to claim 1, characterized in that, The mass ratio of the amount of the endogenous release trigger to the mass of the endogenous solid carbon release agent is (0.4-1.5):1; The ratio of the mass of the water to the total mass of the substrate to be carbonized and activated and the endogenous solid carbon release agent is 0.3 to 0.

6.

8. The homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source according to claim 1, characterized in that, By weight, it includes the following raw materials: substrate to be carbonized and activated: 80-95 parts, endogenous solid carbon release agent: 5-20 parts, endogenous release trigger agent: 3-16 parts, water: 34-58 parts.

9. The application of the homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source as described in any one of claims 1-8 in the preparation of a homogeneous hardened body, characterized in that, Includes the following steps: S1, an activation solution is prepared by mixing an endogenous release trigger agent with water; the substrate to be carbonized and activated is dry-mixed with an endogenous solid carbon release agent to obtain a uniformly dispersed mixed powder. S2, mix the activation solution with the mixed powder, stir evenly to obtain the mixture; S3, the mixture is poured into a mold and sealed for curing to obtain a homogeneous hardened body.

10. The application of the homogeneous carbonized cementitious material based on the chemical controlled release of a solid carbon source according to claim 9 in the preparation of a homogeneous hardened body, characterized in that, The mass concentration of the activation solution is 10-50%.

Images