A fluidized solidification backfill material based on concrete waste slurry

Abstract

The application discloses a kind of based on concrete waste slurry's flow state solidification backfill material, including the following mass fraction of raw materials: concrete waste slurry: 1500-1800 parts;Organic anti-cracking agent: 0.8-1.2 parts;Silicon dioxide: 5-10 parts;Mineral powder: 150-200 parts.The application directly converts concrete waste slurry into flow state solidification backfill material by organic anti-cracking agent and silicon dioxide, without introducing external alkali, reducing the impact on the environment, and shortening the recycling process of waste slurry.Compared with the original treatment method, it has better environmental protection.

Description

Technical Field

[0001] This application relates to a fluidized solidification backfill material based on concrete waste slurry. Background Technology

[0002] Concrete mixing plants generate a large amount of waste slurry during daily production. The cement slurry in this waste slurry contains a significant amount of alkaline substances. If improperly stored or discharged indiscriminately, it can seep into the soil, altering its pH, causing soil compaction, and hindering vegetation growth. Furthermore, harmful substances in the waste slurry may be carried into rivers by rainwater runoff, causing water pollution and impacting aquatic life. In addition, the waste slurry, after drying in the natural environment, generates dust, polluting the air and affecting the quality of life and health of nearby residents. With increasingly stringent environmental protection requirements and intensifying resource scarcity, the need for recycling and utilizing concrete waste slurry from mixing plants is becoming increasingly urgent. Summary of the Invention

[0003] To address the aforementioned issues, this application proposes a fluidized solidified backfill material based on concrete waste slurry, comprising the following raw materials in parts by weight: concrete waste slurry: 1500-1800 parts; organic crack-inhibiting agent: 0.8-1.2 parts; silica: 5-10 parts; mineral powder: 150-200 parts. This application directly converts concrete waste slurry into a fluidized solidified backfill material using the organic crack-inhibiting agent and silica, eliminating the need for external alkalis, reducing environmental impact, and shortening the waste slurry recycling process. Compared to existing treatment methods, it offers better environmental friendliness.

[0004] Preferably, it also includes plain soil, the mass fraction of which is 250-300 parts; the concrete waste slurry is wet-milled for 30-40 minutes before use.

[0005] Preferably, the organic crack-resistant agent is graphene oxide or polypropylene fiber.

[0006] Preferably, the synthesis is carried out according to the following steps:

[0007] 400-500 mesh silica and organic crack-resistant agent are placed in water, and then subjected to the first liquid phase laser treatment under continuous stirring to obtain the first mixture;

[0008] Then, a portion of the concrete waste slurry was added to the first mixture, and a second liquid phase laser treatment was performed under continuous stirring to obtain the second mixture;

[0009] The remaining concrete waste slurry is then added to the second mixture, followed by the addition of mineral powder and soil. The mixture is then stirred and combined to obtain the backfill material.

[0010] This application utilizes liquid-phase laser processing technology to break down, melt, reduce, and rapidly nucleate particles. First, it processes silica particles into micro / nano spherical powders, effectively leveraging the nucleation effect of these micro / nano powders to accelerate the hydration of cementitious materials and improve early strength. Second, under the high energy of laser pulses, the surface properties of silica, graphene oxide, and waste slurry particles can be altered, imbuing the particle surfaces with a large amount of charge, thereby improving particle dispersibility and enhancing the hydration efficiency of cementitious materials. Ultimately, this increases the amount of concrete waste slurry used and reduces production costs. Third, the photothermal effect generated by laser irradiation can reduce graphene oxide. By embedding silica nanospheres within multilayer graphene nanosheets, a sheet-sphere composite structure is achieved, avoiding the agglomeration of large specific surface area nanosheets and nanospheres. More importantly, this sheet-sphere composite structure, as an additive in fluidized solidification backfill materials, can exert a synergistic effect, improving both the early strength and crack resistance and waterproofing properties of the backfill material. Fourth, after laser treatment, silicon dioxide is transformed into spherical nanoparticles, which can effectively exert the ball bearing effect in fluidized solidified backfill materials. Meanwhile, graphene is a two-dimensional layered material with extremely low shear force. This sheet-sphere composite structure will greatly improve the flowability of fluidized solidified backfill materials and enhance the material's performance.

[0011] Preferably, the energy density of the first liquid-phase laser treatment is 800-1000 mJ / pulse. -1 cm -2 Frequency: 8-12Hz, Irradiation time: 30-40min.

[0012] Preferably, the energy density of the second liquid-phase laser treatment is 1500-2000 mJ·pulse. -1 cm -2 Frequency: 8-12Hz, Irradiation time: 10-20min.

[0013] Preferably, the water content in the concrete waste slurry is 40-50 wt%, and the pH is 13-14.

[0014] Preferably, the amount of concrete waste slurry added to the first mixture is 5-10 wt% of the total mass of the concrete waste slurry.

[0015] Preferably, after adding the remaining concrete waste slurry, mineral powder, and raw soil, the mixing time is 2-4 minutes. This application processes the concrete waste slurry in steps. In the first step, the concrete waste slurry added is subjected to laser irradiation, which reduces the particle size to micro-nano scale and makes the particles more loose. This can greatly accelerate the hydration rate of the mineral powder and waste slurry, improve the hydration efficiency, and thus improve the early strength of the backfill material.

[0016] Preferably, the water content in the first mixture is 100-120 parts by mass.

[0017] This application can bring the following beneficial effects:

[0018] 1. This application directly transforms concrete waste slurry into fluidized solidified backfill material by using organic crack-resistant agents and silica super-dispersed early-strength agents. At the same time, it does not require the use of external alkali, reducing the impact on the environment and shortening the recycling process of waste slurry. Compared with the original treatment method, it has better environmental protection.

[0019] 2. This application utilizes liquid-phase laser processing technology to break down, melt, reduce, and rapidly nucleate particles, thereby achieving both the reduction of graphene oxide and the transformation of silica particles into spheres. By embedding silica nanospheres into graphene multilayer nanosheets, a sheet-sphere composite structure is achieved, avoiding the agglomeration of large specific surface area nanosheets and nanospheres. This maximizes the synergistic effect of the graphene / silica sheet-sphere composite structure and improves the performance of the fluidized solidified backfill material obtained in this application.

[0020] 3. This application processes concrete waste slurry in steps. In the first step, the concrete waste slurry is irradiated with laser, and the particle size becomes micro-nano scale. At the same time, the particles become looser, which can greatly accelerate the hydration rate of mineral powder and waste slurry, improve hydration efficiency, and thus improve the early strength of backfill material. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 The change in absolute value of Zeta potential of the first mixture (sample) before and after laser irradiation in Example 1.

[0023] Figure 2 This is an SEM image of the first mixture in Example 1. Detailed Implementation

[0024] To clearly illustrate the technical features of this solution, the following detailed description of specific implementation methods will be provided.

[0025] This application discloses a fluidized solidification backfill material based on concrete waste slurry, comprising the following raw materials in parts by weight:

[0026] Concrete waste slurry: 1500-1800 parts; the concrete waste slurry is wet-milled for 30-40 minutes and then ready for use.

[0027] Organic crack inhibitor: 0.8-1.2 parts;

[0028] Silica: 5-10 parts;

[0029] Mineral powder: 150-200 parts.

[0030] It also includes plain soil, in parts by weight of 250-300.

[0031] The organic anti-cracking agent is graphene oxide or polypropylene fiber.

[0032] The fluidized solidification backfill material described in this application is synthesized according to the following steps:

[0033] S1. Add 5-10 parts of 400-500 mesh silica and 0.8-1.2 parts of organic crack-resistant agent to 100-120 parts of water, and then perform the first liquid phase laser treatment under continuous stirring to obtain the first mixture;

[0034] The energy density of the first liquid-phase laser treatment: 800-1000 mJ / pulse -1 cm -2 Frequency: 8-12Hz, Irradiation time: 30-40min.

[0035] S2. Then, 5-10 wt% of 1500-1800 parts of concrete waste slurry (after ball milling) are added to the first mixture, and a second liquid phase laser treatment is carried out under continuous stirring to obtain the second mixture;

[0036] The water content in the concrete waste slurry is 40-50 wt%, and the pH is 13-14.

[0037] The energy density of the second liquid-phase laser treatment is 1500-2000 mJ·pulse. -1 cm -2 Frequency: 8-12Hz, Irradiation time: 10-20min.

[0038] S3. Then add the remaining concrete waste slurry to the second mixture, and then add 150-200 parts of mineral powder and 250-300 parts of plain soil, and stir and mix to obtain backfill material.

[0039] After adding the remaining concrete waste slurry, mineral powder, and raw soil, the mixing time is 2-4 minutes.

[0040] To characterize the effectiveness of the method of this application, the following embodiments are provided;

[0041] Example 1:

[0042] S101. Add 5 parts of 400-500 mesh silica and 0.8 parts of graphene oxide to 100 parts of water, and then perform a first liquid-phase laser treatment under continuous stirring to obtain a first mixture; Figure 1 As shown, nine samples were taken, and the absolute values ​​of the Zeta potential of the first mixture before and after laser irradiation were measured. The average increase after laser irradiation was 72.7%, indicating a significant improvement in dispersion after laser treatment. The first mixture was characterized by SEM, as shown in the figure. Figure 2 As shown, graphene and silicon dioxide were successfully combined and dispersed evenly. The silicon dioxide was in the form of spherical particles with a micro-nano size, which is beneficial to the hydration of the cementitious material and the impermeability of the backfill material in the later stage.

[0043] The energy density of the first liquid-phase laser treatment was 800 mJ. -1 cm -2 Frequency: 8Hz, Irradiation time: 40min.

[0044] S102. Then, 5 wt% of 1500 parts of concrete waste slurry is added to the first mixture, and a second liquid phase laser treatment is carried out under continuous stirring to obtain the second mixture;

[0045] The water content in the concrete waste slurry is 40 wt%, and the pH is 13.

[0046] The energy density of the second liquid-phase laser treatment: 1500 mJ·pulse -1 cm -2 Frequency: 8Hz, Irradiation time: 20min.

[0047] S103. Then add the remaining concrete waste slurry to the second mixture, then add 150 parts of mineral powder and 250 parts of plain soil, stir and mix for 2 minutes to obtain backfill material No. 1.

[0048] The compressive strength of backfill material No. 1 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.53 MPa; the compressive strength at 3 days was 1.94 MPa; and the compressive strength at 28 days was 3.13 MPa.

[0049] According to JGJ / T 70-2009, the impermeability grade of backfill material No. 1 is determined to be P8.

[0050] Example 2:

[0051] S201. 10 parts of 400-500 mesh silica and 1.2 parts of graphene oxide are placed into 120 parts of water, and then subjected to a first liquid phase laser treatment under continuous stirring to obtain a first mixture;

[0052] The energy density of the first liquid-phase laser treatment was 1000 mJ. -1 cm -2 Frequency: 12Hz, Irradiation time: 30min.

[0053] S202. Then, 10 wt% of 1800 parts of concrete waste slurry is added to the first mixture, and a second liquid phase laser treatment is carried out under continuous stirring to obtain the second mixture;

[0054] The water content in the concrete waste slurry is 50 wt%, and the pH is 14.

[0055] The energy density of the second liquid-phase laser treatment: 2000 mJ·pulse -1 cm -2 Frequency: 12Hz, Irradiation time: 10min.

[0056] S203. Then, put the remaining concrete waste slurry into the second mixture, and then add 200 parts of mineral powder and 300 parts of plain soil. Stir and mix for 4 minutes to obtain backfill material No. 2.

[0057] The compressive strength of backfill material No. 2 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.56 MPa; the compressive strength at 3 days was 1.98 MPa; and the compressive strength at 28 days was 3.08 MPa.

[0058] According to JGJ / T 70-2009, the impermeability grade of backfill material No. 2 is determined to be P8.

[0059] Example 3:

[0060] S301. Add 5 parts of 400-500 mesh silica and 0.8 parts of polypropylene fiber to 100 parts of water, and then perform a first liquid phase laser treatment under continuous stirring to obtain a first mixture;

[0061] The energy density of the first liquid-phase laser treatment was 800 mJ. -1 cm -2 Frequency: 8Hz, Irradiation time: 40min.

[0062] S302. Then, 5 wt% of 1500 parts of concrete waste slurry is added to the first mixture, and a second liquid phase laser treatment is carried out under continuous stirring to obtain the second mixture;

[0063] The water content in the concrete waste slurry is 40 wt%, and the pH is 13.

[0064] The energy density of the second liquid-phase laser treatment: 1500 mJ·pulse -1 cm -2 Frequency: 8Hz, Irradiation time: 20min.

[0065] S303. Then add the remaining concrete waste slurry to the second mixture, then add 150 parts of mineral powder and 250 parts of plain soil, stir and mix for 2 minutes to obtain backfill material No. 3.

[0066] The compressive strength of backfill material No. 3 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.34 MPa; the compressive strength at 3 days was 1.61 MPa; and the compressive strength at 28 days was 2.53 MPa.

[0067] According to JGJ / T 70-2009, the impermeability grade of backfill material No. 3 is determined to be P6.

[0068] Example 4:

[0069] S401. Place 10 parts of 400-500 mesh silica and 1.2 parts of polypropylene fiber into 120 parts of water, and then perform a first liquid phase laser treatment under continuous stirring to obtain a first mixture;

[0070] The energy density of the first liquid-phase laser treatment was 1000 mJ. -1 cm -2 Frequency: 12Hz, Irradiation time: 30min.

[0071] S402. Then, 10 wt% of 1800 parts of concrete waste slurry is added to the first mixture, and a second liquid phase laser treatment is carried out under continuous stirring to obtain the second mixture;

[0072] The water content in the concrete waste slurry is 50 wt%, and the pH is 14.

[0073] The energy density of the second liquid-phase laser treatment: 2000 mJ·pulse -1 cm -2 Frequency: 12Hz, Irradiation time: 10min.

[0074] S403. Then add the remaining concrete waste slurry to the second mixture, then add 200 parts of mineral powder and 300 parts of plain soil, stir and mix for 4 minutes to obtain backfill material No. 4.

[0075] The compressive strength of backfill material No. 4 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.37 MPa; the compressive strength at 3 days was 1.63 MPa; and the compressive strength at 28 days was 2.59 MPa.

[0076] According to JGJ / T 70-2009, the impermeability grade of backfill material No. 4 is determined to be P6.

[0077] Make the following comparative example:

[0078] Comparative Example 1:

[0079] S501. Add 5 parts of 400-500 mesh silica and 0.8 parts of graphene oxide to 100 parts of water, and then ball mill for 40 minutes to obtain the first mixture;

[0080] S502. Then, 10 wt% of 1500 parts of concrete waste slurry is added to the first mixture, and ball milled for 20 min under continuous stirring to obtain the second mixture;

[0081] The water content in the concrete waste slurry is 40 wt%, and the pH is 13.

[0082] S503. Then add the remaining concrete waste slurry to the second mixture, then add 150 parts of mineral powder and 250 parts of plain soil, stir and mix for 2 minutes to obtain No. 5 backfill material.

[0083] The compressive strength of backfill material No. 5 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.11 MPa; the compressive strength at 3 days was 0.47 MPa; and the compressive strength at 28 days was 1.72 MPa.

[0084] According to JGJ / T 70-2009, the impermeability grade of backfill material No. 5 is determined to be P6.

[0085] Comparative Example 2:

[0086] S601. Add 5 parts of 400-500 mesh silica and 0.8 parts of graphene oxide to 100 parts of water, and then perform a first liquid phase laser treatment under continuous stirring to obtain a first mixture;

[0087] The energy density of the first liquid-phase laser treatment was 800 mJ. -1 cm -2 Frequency: 8Hz, Irradiation time: 40min.

[0088] S602. Then, 1500 parts of concrete waste slurry are added to the first mixture, and a second liquid phase laser treatment is carried out under continuous stirring to obtain the second mixture;

[0089] The water content in the concrete waste slurry is 40 wt%, and the pH is 13.

[0090] The energy density of the second liquid-phase laser treatment: 1500 mJ·pulse -1 cm -2 Frequency: 8Hz, Irradiation time: 20min.

[0091] S603. Add 150 parts of mineral powder and 250 parts of plain soil to the second mixture, stir and mix for 2 minutes to obtain backfill material No. 6.

[0092] The compressive strength of backfill material No. 6 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.31 MPa; the compressive strength at 3 days was 0.93 MPa; and the compressive strength at 28 days was 2.35 MPa.

[0093] According to JGJ / T 70-2009, the impermeability grade of backfill material No. 6 is determined to be P6.

[0094] Comparative Example 3:

[0095] S701. Add 5 parts of 400-500 mesh silica and 0.8 parts of graphene oxide to 100 parts of water, and then perform a first liquid phase laser treatment under continuous stirring to obtain a first mixture;

[0096] The energy density of the first liquid-phase laser treatment was 800 mJ. -1 cm -2 Frequency: 8Hz, Irradiation time: 40min.

[0097] S702. Then, a second liquid-phase laser treatment is performed under continuous stirring to obtain a second mixture;

[0098] The energy density of the second liquid-phase laser treatment: 1500 mJ·pulse -1 cm -2 Frequency: 8Hz, Irradiation time: 20min.

[0099] S703. Add 1500 parts of concrete waste slurry to the second mixture, then add 150 parts of mineral powder and 250 parts of plain soil, stir and mix for 2 minutes to obtain backfill material No. 7.

[0100] The water content in the concrete waste slurry is 40 wt%, and the pH is 13.

[0101] The compressive strength of backfill material No. 7 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.29 MPa; the compressive strength at 3 days was 0.83 MPa; and the compressive strength at 28 days was 2.23 MPa.

[0102] According to GB 50164, the impermeability grade of backfill material No. 7 is P6.

[0103] Comparative Example 4:

[0104] S801. 0.8 parts of graphene oxide are added to 100 parts of water, and then subjected to a first liquid phase laser treatment under continuous stirring to obtain a first mixture;

[0105] The energy density of the first liquid-phase laser treatment was 800 mJ. -1 cm -2 Frequency: 8Hz, Irradiation time: 40min.

[0106] S802. Then, 5 wt% of 1500 parts of concrete waste slurry is added to the first mixture, and a second liquid phase laser treatment is carried out under continuous stirring to obtain the second mixture;

[0107] The water content in the concrete waste slurry is 40 wt%, and the pH is 13.

[0108] The energy density of the second liquid-phase laser treatment: 1500 mJ·pulse -1 cm -2 Frequency: 8Hz, Irradiation time: 20min.

[0109] S803. Then add the remaining concrete waste slurry to the second mixture, then add 150 parts of mineral powder and 250 parts of plain soil, stir and mix for 2 minutes to obtain No. 8 backfill material.

[0110] The compressive strength of backfill material No. 8 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.21 MPa; the compressive strength at 3 days was 0.73 MPa; and the compressive strength at 28 days was 1.83 MPa.

[0111] According to JGJ / T 70-2009, the impermeability grade of backfill material No. 8 is P6.

[0112] Comparative Example 5:

[0113] S901. Dry all concrete waste slurry and crush it to obtain 50-100 mesh particles;

[0114] S902. Add 5 parts of 400-500 mesh silica and 0.8 parts of graphene oxide to 100 parts of water, and then perform a first liquid phase laser treatment under continuous stirring to obtain a first mixture;

[0115] The energy density of the first liquid-phase laser treatment was 800 mJ. -1 cm -2 Frequency: 8Hz, Irradiation time: 40min.

[0116] S903. Then, 45 parts of dried concrete waste slurry particles and 30 parts of water are added to the first mixture, and a second liquid phase laser treatment is carried out under continuous stirring to obtain the second mixture.

[0117] The energy density of the second liquid-phase laser treatment: 1500 mJ·pulse -1 cm -2 Frequency: 8Hz, Irradiation time: 20min.

[0118] S904. Then, add 855 parts of dried concrete waste slurry particles and 570 parts of water to the second mixture, then add 150 parts of mineral powder and 250 parts of plain soil, stir and mix for 2 minutes to obtain backfill material No. 9.

[0119] The compressive strength of backfill material No. 9 was determined according to JGJ / T 70-2009. The compressive strength at 1 day was 0.18 MPa; the compressive strength at 3 days was 0.69 MPa; and the compressive strength at 28 days was 1.67 MPa.

[0120] According to JGJ / T 70-2009, the impermeability grade of backfill material No. 9 is determined to be P6.

[0121] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A fluidized solidification backfill material based on concrete waste slurry, characterized in that: The raw materials include the following parts by weight: Concrete waste slurry: 1500-1800 parts; Organic crack inhibitor: 0.8-1.2 parts; Silica: 5-10 parts; Mineral powder: 150-200 parts; Plain soil: 250-300 parts; The organic crack-resistant agent is graphene oxide; And synthesize it according to the following steps: 400-500 mesh silica and organic crack-resistant agent are placed in water, and then subjected to the first liquid phase laser treatment under continuous stirring to obtain the first mixture; Then, a portion of the concrete waste slurry was added to the first mixture, and a second liquid phase laser treatment was performed under continuous stirring to obtain the second mixture; The remaining concrete waste slurry is then added to the second mixture, followed by the addition of mineral powder and soil. The mixture is then stirred and combined to obtain the backfill material.

2. The fluidized solidification backfill material based on concrete waste slurry as described in claim 1, characterized in that: The concrete waste slurry is wet-milled for 30-40 minutes and then ready for use.

3. The fluidized solidification backfill material based on concrete waste slurry as described in claim 1, characterized in that: The energy density of the first liquid-phase laser treatment was 800-1000 mJ. -1 cm -2 Frequency: 8-12Hz, Irradiation time: 30-40min.

4. The fluidized solidification backfill material based on concrete waste slurry as described in claim 1, characterized in that: The energy density of the second liquid-phase laser treatment: 1500-2000 mJ·pulse -1 cm -2 Frequency: 8-12Hz, Irradiation time: 10-20min.

5. The fluidized solidification backfill material based on concrete waste slurry as described in claim 1, characterized in that: The water content in the concrete waste slurry is 40-50 wt%, and the pH is 13-14.

6. The fluidized solidification backfill material based on concrete waste slurry as described in claim 1, characterized in that: The amount of concrete waste slurry added to the first mixture is 5-10 wt% of the total mass of the concrete waste slurry.

7. The fluidized solidification backfill material based on concrete waste slurry as described in claim 1, characterized in that: After adding the remaining concrete waste slurry, mineral powder, and raw soil, the mixing time is 2-4 minutes.

8. The fluidized solidification backfill material based on concrete waste slurry as described in claim 1, characterized in that: The mass fraction of water in the first mixture is 100-120 parts.

Images