High-performance concrete based on building solid waste regenerated micro powder and preparation process thereof

Abstract

The application belongs to the field of building waste recycling, and specifically provides high-performance concrete based on building solid waste regenerated micro powder and a preparation process thereof, which is prepared by mixing raw materials including the following components by mass: 100-115 parts of gravel; 70-75 parts of river sand; 21-28 parts of Portland cement; 16-17.5 parts of water; 7-14 parts of modified regenerated micro powder; and 0.3-0.35 parts of water reducing agent; wherein the modified regenerated micro powder is obtained by surface treatment of building solid waste regenerated micro powder with a modifier; and the concrete obtained by mixing the modified regenerated micro powder has a 28d compressive strength of no less than 42.8 Mpa and a flexural strength of no less than 5.1 Mpa, and has good durability.

Description

Technical Field

[0001] This application belongs to the field of construction waste recycling technology, and in particular relates to a high-performance concrete based on recycled micro powder from construction solid waste and its preparation process. Background Technology

[0002] Concrete, as the most widely used man-made building material in the world today, is basically composed of cementitious materials, coarse and fine aggregates, mixing water, and admixtures. During the curing process of concrete, cement and water undergo a hydration reaction to generate hydration products such as hydrated calcium silicate gel, calcium hydroxide, and ettringite. These products bind the aggregate particles together to form a composite material system with high strength and durability.

[0003] With the rapid advancement of urbanization in my country, the amount of construction demolition waste generated is increasing year by year. Through multi-stage crushing and screening processes, most of the demolition concrete can be converted into recycled aggregate. However, approximately 15%-20% of recycled construction solid waste powder with a particle size of less than 75 micrometers is also generated. The main components of recycled construction solid waste powder include hardened cement paste powder, unhydrated cement particles, fine quartz sand powder, and a small amount of clay minerals. It has low activity, high water demand, and uneven particle size distribution. Compared to natural aggregate concrete, recycled aggregate has an old cement mortar layer attached to its surface. This results in multiple interfaces in recycled aggregate concrete: a primary interface transition zone between the old cement mortar and natural aggregate, a secondary interface transition zone between the recycled aggregate and new cement paste, and a micro-crack and pore network within the old cement mortar. This high porosity and crystal orientation microstructure makes the interface transition zone the weakest link in recycled aggregate concrete. Currently, the reinforcement methods for recycled aggregate mainly focus on coating modification and carbonation treatment, which are costly and difficult to achieve long-lasting reinforcement effects.

[0004] Therefore, there is a need to find a high-performance concrete based on recycled building waste powder and its preparation process that can enhance the strength of recycled aggregate concrete and improve its service durability. Summary of the Invention

[0005] To address the aforementioned issues and further enhance the strength and durability of recycled aggregate concrete, this application provides a high-performance concrete based on recycled construction waste micropowder and its preparation process.

[0006] This application first provides a preparation process for high-performance concrete based on recycled micro powder from construction solid waste, which is prepared by mixing raw materials including the following parts by weight: 100-115 parts crushed stone; 70-75 parts river sand; 21-28 parts silicate cement; 16-17.5 parts water; 7-14 parts modified recycled micro powder; and 0.3-0.35 parts water-reducing agent.

[0007] The modified recycled micro powder is obtained by surface treatment of recycled micro powder from construction solid waste with a modifier;

[0008] The modifier is obtained by self-assembly of phosphorylated chitosan and sulfonated cellulose, and the preparation steps include the following:

[0009] Take the phosphorylated chitosan aqueous solution, slowly add it dropwise to the sulfonated cellulose aqueous solution, stir, then adjust the pH value, continue stirring, then centrifuge, take the precipitate, wash and dry it to obtain the final product.

[0010] Furthermore, the preparation method of the phosphorylated chitosan includes the following:

[0011] Chitosan, urea and 85% phosphoric acid were mixed and reacted at a high temperature. After precipitation with anhydrous ethanol, washing and drying were performed to obtain phosphorylated chitosan.

[0012] The mass-to-volume ratio of chitosan, urea, and 85% phosphoric acid used is (5-5.5)g:(25-28)g:(250-300)mL;

[0013] The heating reaction involves heating to 115-122℃ and holding the temperature constant for 3-4 hours.

[0014] Furthermore, the method for preparing the sulfonated cellulose includes the following:

[0015] Microcrystalline cellulose was dispersed and stirred in a water bath. Then, sulfur trioxide pyridine was added, and the pH was adjusted to neutral. The precipitate was then collected by filtration, washed with anhydrous ethanol, and dried under vacuum to obtain sulfonated cellulose.

[0016] The mass ratio of the microcrystalline cellulose to sulfur trioxide pyridine used is (9.5-10.5):(10.2-11.7).

[0017] By adopting the above technical solution, in the highly alkaline environment of cement hydration, the negative charge carried by the sulfonate group after dissociation attracts the positively charged calcium ions through electrostatic interaction, causing the calcium ions to concentrate around cellulose. At the same time, cellulose can act as a template agent to promote the mineralization of CSH and the growth of ettringite, thereby strengthening the interface zone.

[0018] Furthermore, the surface treatment employs an impregnation method, a blending method, or a combination of impregnation and blending.

[0019] The impregnation method includes the following steps:

[0020] Prepare a treatment solution with a mass fraction of 0.25%-0.5% using the modifier, mix it with the recycled micro powder from construction solid waste at a solid-liquid ratio of 1:1, stir and treat at 30±2℃ for 30-60 minutes, and after solid-liquid separation, dry, crush and sieve to obtain the final product.

[0021] The blending process includes the following steps:

[0022] Prepare a 0.5% (w / w) solution of the modifier, spray it onto the recycled construction solid waste powder, control the moisture content to 15%-25%, age for 2-4 hours, dry, grind, and sieve to obtain the final product.

[0023] The impregnation-blending method includes the following steps:

[0024] Prepare a treatment solution with a mass fraction of 0.25% using the modifier. Impregnate the recycled micro powder from construction solid waste for 20-30 minutes. After solid-liquid separation, control the moisture content of the filter cake to 25%-35%. Then, add dry modifier powder and mix vigorously. After aging, dry, grind, and sieve to obtain the final product.

[0025] This application also provides a high-performance concrete based on recycled construction solid waste powder, which is prepared using the above-mentioned preparation process.

[0026] Compared with the prior art, this application has the following beneficial effects:

[0027] 1. This application obtains a modifier by self-assembling phosphorylated chitosan and sulfonated cellulose, which is used for surface modification of recycled building solid waste powder. The strong coordination between the phosphate groups of phosphorylated chitosan and calcium ions on the surface of recycled building solid waste powder, and the induced mineralization effect of the sulfonate groups of sulfonated cellulose on CSH gel, construct an active interface layer with multifunctional synergistic effect on the surface of recycled building solid waste powder.

[0028] 2. During the concrete curing stage, the modified recycled micro powder prepared in this application can induce the growth of ettringite through the active interface layer, which penetrates the interface transition zone and forms a "penetration-anchoring" three-dimensional network structure between the aggregate and the cement matrix, effectively transferring and dispersing stress and inhibiting the initiation and propagation of interface cracks.

[0029] 3. Concrete prepared using the modified recycled micro powder of this application, within the range of 20%-40% recycled micro powder replacement rate, has a 28-day compressive strength ≥42.8 MPa and a flexural strength ≥5.1 MPa, while the electrical flux and freeze-thaw resistance are significantly improved.

[0030] 4. This application provides three surface modification treatment processes: impregnation, blending, and combined impregnation-blending. The process can be flexibly selected according to the quality of the recycled micro powder from construction solid waste and the engineering requirements. The process is simple, easy to operate, and easy to industrialize. Attached Figure Description

[0031] Figure 1 The results of freeze-thaw cycle tests for Examples 1-3 and Comparative Examples 1-2 of this application are shown. Detailed Implementation

[0032] To make the inventive purpose, technical solution, and beneficial technical effects of this application clearer, the following detailed description of this application is provided in conjunction with embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0033] When using “including,” “having,” and “contains” as described herein, the intention is to cover non-exclusive inclusion, unless an explicit qualifying term such as “only,” “consisting of,” etc., is used, in which case another component may be added.

[0034] The terms "preferred," "more preferably," "better," and "even better" used in this application refer to embodiments of this application that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this application. That is, in this application, "preferred," "more preferably," "better," and "even better" are merely descriptions of implementations or embodiments with better effects, but do not constitute a limitation on the scope of protection of this application.

[0035] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0036] In this application, "at least one" means one or more, such as one, two, or more. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layered" means at least two layers, such as two layers, three layers, etc., unless otherwise explicitly specified. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0037] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0038] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, the method comprising steps (a) and (b) indicates that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0039] In this application, "above" or "below" includes the stated number. For example, "below 1" includes 1.

[0040] In this application, room temperature refers to 0~40℃, including but not limited to 10~40℃, or further to 20~30℃.

[0041] In some embodiments of this application, during the preparation of phosphorylated chitosan, the mass-volume ratio of chitosan, urea, and 85% phosphoric acid is (5-5.5)g:(25-28)g:(250-300)mL. For example, it can be 5g:25g:250mL, 5.2g:26g:275mL, 5.3g:27g:285mL, 5.4g:28g:295mL, or 5.5g:28g:300mL.

[0042] In some embodiments of this application, the heating reaction during the preparation of phosphorylated chitosan is as follows: heating to 115-122°C and reacting at a constant temperature for 3-4 hours. For example, heating to 115°C and reacting at a constant temperature for 4 hours, heating to 118°C and reacting at a constant temperature for 3.8 hours, heating to 120°C and reacting at a constant temperature for 3.5 hours, heating to 121°C and reacting at a constant temperature for 3.3 hours, and heating to 122°C and reacting at a constant temperature for 3 hours.

[0043] In some embodiments of this application, the mass ratio of microcrystalline cellulose to sulfur trioxide pyridine used in the preparation of sulfonated cellulose is (9.5-10.5):(10.2-11.7), for example, it can be 9.5:10.2, 9.8:10.5, 10:11, 10.2:11.5, or 10.5:11.7.

[0044] The present application will be further illustrated by the following examples, but these examples do not limit the scope of the present application.

[0045] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this application, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. All reagents or instruments whose manufacturers are not specified are conventional products that can be purchased commercially. In addition to the specific methods, equipment, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description in this application, any prior art methods, equipment, and materials similar to or equivalent to those described, used, or made by the methods, equipment, and materials in the embodiments of this application may be used to implement this application.

[0046] Preparation Example

[0047] Weigh 5g of chitosan (degree of deacetylation ≥90%) and 25g of urea into a 500mL three-necked round-bottom flask. Then add 300mL of 85% phosphoric acid. Set the magnetic stirring speed to 300rpm, heat to 115℃, reflux, and maintain the temperature for 3 hours. After the reaction is complete, allow it to cool naturally to room temperature. Slowly pour the reaction mixture into 500mL of anhydrous ethanol to allow for complete precipitation. Collect the precipitate at the bottom under vacuum filtration, and wash twice with 150mL of acetone, stirring for 5 minutes each time. After washing, transfer the filter cake to a vacuum drying oven and dry at 80℃ and a vacuum degree ≤-0.09MPa for 12 hours. Grind the dried product in an agate mortar and pestle, and pass through a 200-mesh sieve to obtain phosphorylated chitosan.

[0048] Weigh 9.5 g of microcrystalline cellulose, dry it thoroughly at 105 °C, and after cooling, place it in a 250 mL round-bottom flask. Add 80 mL of DMF solution and stir in a 50 °C water bath for 1 hour. Add 10.2 g of pyridine trioxide in three batches, with an interval of 5 minutes between each batch. After the addition is complete, continue stirring for 3 hours. After the reaction is complete, cool to room temperature and adjust the pH to 7.0 with 10% sodium hydroxide solution. Then, slowly pour the reaction mixture into 400 mL of anhydrous ethanol and collect the precipitate by vacuum filtration. Wash three times with 200 mL of anhydrous ethanol, stirring for 10 minutes each time. After washing, dry the filter cake at 60 °C and a vacuum degree ≤ -0.09 MPa for 12 hours, grind it through a 200-mesh sieve, and obtain sulfonated cellulose.

[0049] Example 1

[0050] The specific preparation process of high-performance concrete in this embodiment is as follows:

[0051] The concrete mix proportions per cubic meter are as follows: 280 kg of ordinary Portland cement P.O42.5, 70 kg of modified recycled micro-powder, 700 kg of natural river sand (fineness modulus 2.6), 1150 kg of natural crushed stone (5-25 mm continuous gradation), 175 kg of mixing water, 3.5 kg of polycarboxylate superplasticizer, water-cement ratio 0.5, and the substitution rate of modified recycled micro-powder for cement is 20%.

[0052] Add cement, modified recycled micro powder, river sand, and crushed stone to a mixer and dry mix for 60 seconds. Then add 80% of the mixing water and mix for 90 seconds. Next, dilute the water-reducing agent with the remaining mixing water and add it to the mixer, then continue mixing for 120 seconds. After discharging, pour the concrete mixture into test molds, vibrate to compact it, cover with plastic film, and let it stand at 20±2℃ for 24 hours. After that, remove the molds and move the mixture to a standard curing room (temperature 20±2℃, relative humidity ≥95%) for curing until the specified age.

[0053] The specific steps for preparing the modified recycled micro powder in this embodiment are as follows:

[0054] 1000g of recycled construction solid waste powder (specific surface area 422m² / kg, apparent density 2.45g / cm³) was treated using the impregnation method. 5.0g of modifier was weighed and added to 1000mL of deionized water. Glacial acetic acid was added to adjust the pH to 5.0, and the mixture was stirred and dissolved at 30℃. The mixture was then ultrasonically dispersed for 15 minutes to obtain a 0.5% (w / w) treatment solution. The recycled construction solid waste powder was added to the treatment solution at a solid-liquid ratio of 1:1, and the mixture was stirred at 30℃ for 45 minutes. Vacuum filtration was performed to separate the powder. The filter cake was dried to constant weight at 105℃, crushed, and passed through a 0.15mm sieve to obtain the modified recycled powder.

[0055] In this embodiment, the preparation steps of the modifier are as follows:

[0056] Weigh 5.0 g of phosphorylated chitosan, add deionized water and sonicate for 30 minutes. Then add glacial acetic acid to adjust the pH to 4.5 to obtain a 0.8% (w / w) phosphorylated chitosan aqueous solution. Weigh 2.5 g of sulfonated cellulose, add deionized water and sonicate for 25 minutes to obtain a 0.5% (w / w) sulfonated cellulose aqueous solution. Then adjust the pH to 5.0. Under stirring, add the phosphorylated chitosan aqueous solution dropwise to the sulfonated cellulose aqueous solution at a rate of 10 mL / min. After the addition is complete, stir for 30 minutes. Then adjust the pH to 6.0 with sodium hydroxide solution and continue stirring for 30 minutes. Then centrifuge at 10,000 rpm for 15 minutes. Wash the precipitate twice with deionized water and dry thoroughly to obtain the modifier.

[0057] Example 2

[0058] The specific preparation process of high-performance concrete in this embodiment is as follows:

[0059] The concrete mix proportions per cubic meter are as follows: 245 kg of ordinary Portland cement P.O42.5, 105 kg of modified recycled micro powder, 700 kg of natural river sand, 1150 kg of natural crushed stone, 175 kg of mixing water, 3.5 kg of polycarboxylate superplasticizer, water-cement ratio of 0.5, and the substitution rate of modified recycled micro powder for cement is 30%.

[0060] The specific steps for preparing the modified recycled micro powder in this embodiment are as follows:

[0061] Take 1000g of recycled construction waste powder and process it using the blending method. Weigh 2.5g of modifier, add deionized water and stir, then add glacial acetic acid to adjust the pH to 5.0, preparing a 0.5% (w / w) treatment solution. Add the recycled construction waste powder to a high-performance mixer and run it at 250 rpm. Spray the treatment solution evenly onto the recycled construction waste powder using a spray method for 12 minutes, controlling the total moisture content to 20%. After spraying, continue mixing for 8 minutes, transfer the material to a sealed container, and age it at 25℃ for 3 hours. After aging, dry the material at 105℃ until the moisture content is ≤1.0%, ball mill it for 15 minutes, and pass it through a 0.15mm sieve to obtain modified recycled powder.

[0062] The remaining steps are the same as in Example 1.

[0063] Example 3

[0064] The specific preparation process of high-performance concrete in this embodiment is as follows:

[0065] The concrete mix proportions per cubic meter are as follows: 210 kg of ordinary Portland cement P.O42.5, 140 kg of modified recycled micro powder, 700 kg of natural river sand, 1150 kg of natural crushed stone, 175 kg of mixing water, 3.5 kg of polycarboxylate superplasticizer, water-cement ratio of 0.5, and the substitution rate of modified recycled micro powder for cement is 40%.

[0066] The specific steps for preparing the modified recycled micro powder in this embodiment are as follows:

[0067] Take 1000g of recycled construction solid waste powder and treat it using an impregnation-blending method. Weigh 2.5g of modifier, add it to deionized water and stir to adjust the pH to 5.0, preparing a treatment solution with a mass fraction of 0.25%. Add the recycled construction solid waste powder to the treatment solution at a solid-liquid ratio of 1:1 and stir at 30℃ for 20 minutes. Vacuum filter separation is performed, controlling the moisture content of the filter cake to 30%. The wet filter cake is then transferred to a high-intensity mixer, and 2.0g of modifier is added. The mixture is then vigorously mixed at 400rpm for 12 minutes. The mixture is transferred to a sealed container and aged at 25℃ for 3 hours. After aging, the material is dried at 105℃ to constant weight, ball-milled for 15 minutes, and passed through a 0.15mm sieve to obtain modified recycled powder.

[0068] The remaining steps are the same as in Example 1.

[0069] Comparative Example 1

[0070] The specific preparation process of high-performance concrete in this comparative example is as follows:

[0071] The concrete mix proportions per cubic meter are as follows: 280 kg of ordinary Portland cement P.O42.5, 70 kg of modified recycled powder, 700 kg of river sand, 1150 kg of crushed stone, 175 kg of water, 3.5 kg of polycarboxylate superplasticizer, water-cement ratio of 0.5, and the substitution rate of modified recycled powder for cement is 20%.

[0072] The specific preparation steps of the modified recycled micro powder in this comparative example are as follows:

[0073] Take 1000g of recycled construction waste micropowder and process it using the blending method. Weigh 5g of chitosan and 5g of microcrystalline cellulose, add deionized water and stir. Add glacial acetic acid to adjust the pH to 5.0, and prepare a mixed solution containing 0.25% chitosan and 0.25% microcrystalline cellulose. Add the recycled construction waste micropowder to a high-performance mixer and run it at 250 rpm. Spray the treatment solution evenly onto the recycled construction waste micropowder using a spray method for 12 minutes, controlling the total moisture content to 20%. After spraying, continue mixing for 8 minutes, transfer the material to a sealed container, and age it at 25℃ for 3 hours. After aging, dry the material at 105℃ until the moisture content is ≤1.0%, ball mill it for 15 minutes, and pass it through a 0.15mm sieve to obtain modified recycled micropowder.

[0074] The remaining steps are the same as in Example 1.

[0075] Comparative Example 2

[0076] The specific preparation process of high-performance concrete in this comparative example is as follows:

[0077] The concrete mix proportions per cubic meter are as follows: 245 kg of ordinary Portland cement P.O42.5, 105 kg of recycled construction waste powder, 700 kg of river sand, 1150 kg of crushed stone, 175 kg of water, 3.5 kg of polycarboxylate superplasticizer, water-cement ratio of 0.5, and the replacement rate of cement with recycled construction waste powder is 30%.

[0078] The remaining steps are the same as in Example 1.

[0079] Performance testing

[0080] 1. Initial slump

[0081] The tests were conducted in accordance with the relevant test contents of the national standard GB / T50081-2016.

[0082] 2. 28-day compressive / flexural strength

[0083] The tests were conducted in accordance with the relevant test contents of the national standard GB / T50081-2019.

[0084] 3. 28 electrical flux / 300 freeze-thaw cycles relative dynamic elastic modulus

[0085] The tests were conducted in accordance with the relevant test contents of the national standard GB / T50082-2009.

[0086] The test results are shown in Table 1 and Figure 1 As shown.

[0087] Table 1. Concrete performance test results of Examples 1-3 and Comparative Examples 1-2

[0088]

[0089] Take Examples 1-3 and Comparative Examples 1-2 and refer to Table 1 and Figure 1It can be seen that the modified recycled micropowder prepared using the three treatment methods in Examples 1-3 of this application has a 28-day compressive strength of ≥42.8 MPa and a flexural strength of ≥5.1 MPa in concrete, which is significantly higher than that of the comparative example. The modified recycled micropowder in Comparative Example 1 only mixed untreated chitosan, microcrystalline cellulose and recycled micropowder from construction solid waste, resulting in poor synergistic effect between the components and no significant improvement in concrete properties after mixing. In Comparative Example 2, due to the porosity and other problems inherent in the recycled micropowder from construction solid waste, the compressive and flexural strengths of the concrete decreased to varying degrees after mixing, and after 300 freeze-thaw cycles, the relative dynamic modulus of elasticity was only 52.1%, indicating freeze-thaw damage after the concrete cycle test and a risk of cracking in long-term use. Furthermore, combining the data from Examples 1-3 and Comparative Example 2, the performance of concrete decreased with the increase of the micropowder replacement rate, but the results of the example schemes were still significantly better than the control group of untreated recycled micropowder from construction solid waste.

[0090] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A process for preparing high-performance concrete based on recycled construction solid waste powder, characterized in that, It is prepared by mixing the following raw materials in parts by weight: 100-115 parts crushed stone; 70-75 parts river sand; 21-28 parts silicate cement; 16-17.5 parts water; 7-14 parts modified recycled powder; and 0.3-0.35 parts water-reducing agent. The modified recycled micro powder is obtained by surface treatment of recycled micro powder from construction solid waste with a modifier; The modifier is obtained by self-assembly of phosphorylated chitosan and sulfonated cellulose, and the preparation steps include the following: Take the phosphorylated chitosan aqueous solution, slowly add it dropwise to the sulfonated cellulose aqueous solution, stir, then adjust the pH value, continue stirring, then centrifuge, take the precipitate, wash and dry it to obtain the final product.

2. The preparation process of high-performance concrete based on recycled construction solid waste powder according to claim 1, characterized in that, The preparation method of the phosphorylated chitosan includes the following: Chitosan, urea, and 85% phosphoric acid were mixed and reacted at a high temperature. The mixture was then precipitated with anhydrous ethanol, washed, and dried to obtain phosphorylated chitosan.

3. The preparation process of high-performance concrete based on recycled construction solid waste powder according to claim 2, characterized in that, The mass-volume ratio of chitosan, urea and 85% phosphoric acid used is (5-5.5)g:(25-28)g:(250-300)mL; the heating reaction is carried out by heating to 115-122℃ and reacting at a constant temperature for 3-4 hours.

4. The preparation process of high-performance concrete based on recycled construction solid waste powder according to claim 1, characterized in that, The method for preparing the sulfonated cellulose includes the following: Microcrystalline cellulose was dispersed and stirred in a water bath. Then, sulfur trioxide pyridine was added, and the pH was adjusted to neutral. The precipitate was then collected by filtration, washed with anhydrous ethanol, and dried under vacuum to obtain sulfonated cellulose.

5. The preparation process of high-performance concrete based on recycled construction solid waste powder according to claim 4, characterized in that, The mass ratio of microcrystalline cellulose to sulfur trioxide pyridine used is (9.5-10.5):(10.2-11.7).

6. The preparation process of high-performance concrete based on recycled construction solid waste powder according to claim 1, characterized in that, The surface treatment employs impregnation, blending, or a combination of impregnation and blending.

7. The preparation process of high-performance concrete based on recycled construction solid waste powder according to claim 6, characterized in that, The impregnation method includes the following steps: Prepare a treatment solution with a mass fraction of 0.25%-0.5% by the modifier, mix it with the recycled micro powder of construction solid waste at a solid-liquid ratio of 1:1, stir and treat at 30±2℃ for 30-60 minutes, and after solid-liquid separation, dry, crush and sieve to obtain the final product.

8. The preparation process of high-performance concrete based on recycled construction solid waste powder according to claim 6, characterized in that, The blending process includes the following steps: The modifier is prepared into a treatment solution with a mass fraction of 0.5%, which is sprayed onto the recycled micro powder of construction solid waste. The moisture content is controlled at 15%-25%, aged for 2-4 hours, dried, ground, and sieved to obtain the final product.

9. The preparation process of high-performance concrete based on recycled construction solid waste powder according to claim 6, characterized in that, The impregnation-blending method includes the following steps: Prepare a treatment solution with a mass fraction of 0.25% using the modifier. Impregnate the recycled micro powder from construction solid waste for 20-30 minutes. After solid-liquid separation, control the moisture content of the filter cake to 25%-35%. Then, add dry modifier powder and mix vigorously. After aging, dry, grind, and sieve to obtain the final product.

10. A high-performance concrete based on recycled construction solid waste powder, characterized in that, It is prepared using the preparation process described in any one of claims 1-9.

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