A full-solid-waste light aggregate grouting material, a preparation method thereof and application thereof

Abstract

The application discloses a kind of full solid waste light aggregate grouting material and its preparation method and application, belong to solid waste resource and road engineering material technical field.The grouting material is by cementing component (coal gangue powder, carbide slag, desulfurization gypsum), light porous aggregate and fine aggregate, mineralization modified recycled fiber (surface deposition calcium carbonate layer), mineralization system product mixing liquid and admixture composition, realize fiber interface enhancement by carbide slag wet mineralization, significantly improve post-crack bearing capacity.Through cementing component classification calcination activation, mineralization slurry modified fiber, aggregate pretreatment, dry powder premixing, liquid into slurry and fiber incorporation etc.Step.Application field covers roadbed backfill, bridge backfill and foundation reinforcement engineering.The application utilizes industrial solid waste and waste fishing net fiber, realizes resource utilization, reduces carbon emission;Grouting material has the advantages of light weight, high strength, controllable fluidity, good crack resistance, etc., suitable for engineering reinforcement under complex geological conditions, with environmental protection and economy.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization and road engineering materials technology, specifically relating to a lightweight aggregate grouting material made entirely of solid waste, its preparation method and application. Background Technology

[0002] Grouting materials, as important building and civil engineering materials, are widely used in projects such as roadbed backfilling, bridge abutment backfilling, and foundation reinforcement. Traditional grouting materials mostly rely on cement-based systems. Although they have good strength and fluidity, the high energy consumption and carbon emissions during cement production put significant pressure on the environment. At the same time, while cement-based grouting materials possess a certain compressive strength, their brittleness, especially under low-density and porous structures, often leads to problems such as drying shrinkage cracking and crack propagation, affecting long-term durability and structural stability.

[0003] In recent years, with the increasing demand for green building materials, researchers have attempted to replace some cement with industrial solid waste such as coal gangue, steel slag, desulfurized gypsum, and fly ash to prepare all-solid-waste grouting materials. These materials have certain advantages in reducing carbon emissions, but the following problems still exist:

[0004] 1. Low-density lightweight aggregate systems have poor crack resistance.

[0005] 2. The early strength of solid waste-based grouting materials is low, making it difficult to meet the requirements of rapid construction and short construction period.

[0006] 3. Poor interfacial adhesion, especially insufficient activity of mineral components in the solid waste system, leads to weak bonding between fibers or aggregates and the slurry, affecting the toughness and stability of the material.

[0007] 4. Existing fiber modification methods mostly employ chemical treatments, such as silane coupling agents. However, these modification methods often involve high costs and complex processes, and the modification effect is limited.

[0008] Therefore, there is an urgent need for a grouting material solution that is based on solid waste, can be pumped and self-compacting, is resistant to segregation and bleeding, has early strength and rapid hardening, and is low in density and high in toughness, and achieves synergy between carbon fixation process and interface enhancement. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a lightweight aggregate grouting material made entirely from solid waste, its preparation method, and its application. Through an integrated approach of "wet mineralization of carbide slag—in-situ deposition on fiber surface—mineralization products participating in mixing," it solves the shortcomings of existing solid waste grouting materials in terms of pumpability stability, early performance, crack resistance toughness, and interfacial bonding, while also achieving carbon sequestration and emission reduction effects.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0011] A lightweight aggregate grouting material made entirely of solid waste includes a cementitious component, an aggregate component, a reinforcing component, a mixing liquid, and admixtures, wherein:

[0012] The cementitious components, by mass fraction, include 30-38 parts of pretreated coal gangue powder, 40-52 parts of calcium carbide slag, and 15-26 parts of desulfurized gypsum;

[0013] The aggregate composition includes 50-250 parts of lightweight porous aggregate and 10-150 parts of fine aggregate;

[0014] The reinforcing component is recycled fiber, and the dosage is 0.05~1.5% of the mass of the cementitious component. The recycled fiber is mineralized modified waste fishing net fiber, and its surface has a calcium carbonate deposit layer generated by wet mineralization of carbide slag and deposited in situ.

[0015] The mixing liquid is a combination of water and one or more mineralization system products, wherein the mineralization system products are selected from mineralization supernatant or mineralization slurry; the mass ratio of the mixing liquid to the cementing component is (0.35~0.60):1;

[0016] The admixture is one or more of water-reducing agents, water-retaining agents, and defoamers, and the dosage is 0 to 1.0% of the mass of the gelling component.

[0017] Further, the cementitious component is prepared through the following steps: coal gangue powder, carbide slag, and desulfurized gypsum are each passed through a 200-mesh sieve and then mixed according to a specified ratio to obtain a mixture; deionized water is added to the mixture to make it slightly moist, and the mixture is pressed into test cakes; the test cakes are then placed in an electric furnace for graded calcination and activation; after being removed from the furnace, the mixture is rapidly cooled, and then crushed, ball-milled, and sieved to obtain the cementitious component, wherein the D50 of the cementitious component is 15~30 μm.

[0018] Further, the staged calcination activation is as follows: the initial temperature is 50~100℃, then increased to 900℃ at a rate of 10~20℃ / min; then increased to 1200℃ at a rate of 5~10℃ / min and held at that temperature for 40~60 min. Figure 2 As shown.

[0019] Furthermore, the mineralized modified waste fishing net fiber is prepared by the following method: waste fishing net fiber is added to a mineralization system, causing calcium carbonate to nucleate heterogeneously on the surface of the waste fishing net fiber and deposit in situ. The mixture is then filtered and surface-dried to obtain the mineralized modified waste fishing net fiber. The surface deposition layer of the mineralized modified fiber corresponds to a fiber weight gain of 0.5% to 10%.

[0020] Furthermore, the preparation method of the mineralization system includes the following steps: preparing a mineralization slurry with a solid content of 5%~35% by reacting carbide slag and water; then introducing a CO2-containing gas with a volume fraction of 5%~100% into the mineralization slurry and carrying out a wet mineralization reaction for 45~60 minutes to obtain the mineralization system.

[0021] Furthermore, the lightweight porous aggregate is coal gangue aggregate and / or steel slag aggregate with a particle size of 2~20 mm; the fine aggregate is river sand / aeolian sand with a particle size of 0.1~2.36 mm.

[0022] Furthermore, the lightweight porous aggregate is obtained by pre-soaking in a mineralization supernatant for 0.5-30 minutes and then surface drying, with the mineralization supernatant collected during the preparation process of the mineralization system.

[0023] A method for preparing the aforementioned all-solid-waste lightweight aggregate grout, such as... Figure 1 As shown, it includes the following steps:

[0024] S1. Dry powder premixing: The gelling component and the aggregate component are stirred at 200 r / min for 2~3 min to obtain a mixed dry material;

[0025] S2. Adding liquid to form slurry: Add mixing liquid and additives to the mixed dry material described in S1, and stir at 350 r / min for 3 to 5 min to obtain slurry;

[0026] S3. Adding reinforcing components: Add reinforcing components to the slurry described in S2, and continue stirring at 500 r / min for 5~8 min to obtain the all-solid waste lightweight aggregate grout.

[0027] Application of a lightweight aggregate grout, as described above, in roadbed backfilling, bridge abutment backfilling, or foundation reinforcement projects.

[0028] The application of mineralized modified recycled fiber as an interface reinforcement component in all-solid waste-based grouting material, wherein the mineralized modified recycled fiber is waste fishing net fiber with a calcium carbonate layer deposited in situ by wet mineralization of carbide slag on its surface, used to improve the post-cracking load-bearing capacity and toughness of the grouting material.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] (1) Synergistic effect of interface enhancement and carbon fixation: Calcium carbonate generated by wet mineralization of carbide slag is deposited in situ on the fiber surface to form a rough mineral layer, which improves the interlocking and friction energy consumption of the fiber and matrix interface, thereby enhancing the load-bearing capacity and toughness after cracking, while realizing CO2 mineralization fixation.

[0031] (2) Improved mixing stability: The introduction of calcium carbonate particles and mineralization supernatant into the mixing process can provide crystal nucleation effect and ion environment regulation, improve rheological stability, and reduce the risk of segregation and bleeding.

[0032] (3) Mainly solid waste and can be scaled up: Both the cementitious component and the aggregate component are mainly solid waste. The preparation process is wet mineralization and conventional stirring and dispersion process, which is convenient for on-site or pre-mixed application.

[0033] (4) Low density is achieved by constructing a skeleton through the dual aggregate gradation of lightweight porous aggregate and fine aggregate in the aggregate component, so as to achieve both low density and pumpable self-compacting properties.

[0034] In summary, the grouting material of the present invention is a fiber-containing, pumpable, self-compacting, all-solid waste lightweight aggregate grouting material that utilizes the wet mineralization of carbide slag to deposit calcium carbonate in situ on the surface of recycled fibers and introduces the mineralization system products into the mixing process. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A schematic diagram of the preparation process of the all-solid-waste lightweight aggregate grouting material provided by the present invention;

[0037] Figure 2 This is a temperature gradient diagram for staged calcination activation.

[0038] Figure 3 The XRD pattern of the solid waste gelling components prepared in Example 1 of this invention;

[0039] Figure 4 The XRD pattern of the all-solid-waste lightweight aggregate grout specimen prepared in Example 1 of this invention;

[0040] Figure 5 The image shows the TG-DSC spectrum of the all-solid waste lightweight aggregate grouting material specimen prepared in Example 1 of this invention. Detailed Implementation

[0041] To gain a deeper understanding of this invention, we will provide a comprehensive and detailed description. However, this invention has various implementations and is not limited to the specific examples listed herein. These examples are presented to enhance a full understanding of the disclosure of this invention.

[0042] Example 1

[0043] Preparation of the cementitious component: 30 parts of coal gangue powder, 40 parts of calcium carbide slag, and 20 parts of desulfurized gypsum were weighed out separately, passed through a 200-mesh sieve, and mixed evenly. Deionized water was sprayed into the mixture to adjust the moisture content to approximately 5% (it should clump together when squeezed but crumble easily when released). The mixture was then pressed into round test cakes with a diameter of 100 mm and a thickness of 10 mm. The test cakes were placed in a programmable temperature-controlled electric furnace for staged calcination activation: starting at 80℃, the temperature was increased to 900℃ at a rate of 15℃ / min, then increased to 1200℃ at a rate of 8℃ / min, and held at 1200℃ for 50 min. After calcination, the test cakes were quickly transferred to a metal heat sink to cool to room temperature. The cooled blocks were coarsely crushed by a jaw crusher, finely ground by a planetary ball mill, and sieved to obtain a cementitious component of all solid waste with a D50 of approximately 25 μm.

[0044] Mineralization system: Calcium carbide slag is mixed with water to prepare a mineralization slurry with a solid content of 20%. CO2 gas (volume fraction of 30%) is continuously introduced into the slurry, and a wet mineralization reaction is carried out at room temperature for 45 min to obtain a mineralization system containing fine calcium carbonate particles. The supernatant of the mineralization process can be collected at the same time.

[0045] Subsequently, waste fishing net fibers with a length of 6 mm were added to the mineralization system and stirred to allow calcium carbonate to nucleate heterogeneously on the fiber surface and deposit in situ. After the reaction was completed, the fibers were filtered to separate them and then surface-dried in an oven at 60°C to obtain mineralized modified waste fishing net fibers with a calcium carbonate deposition layer on the surface, which was the reinforcing component. The fiber weight gain was measured to be 3.2%.

[0046] Lightweight aggregate pretreatment: Immerse coal gangue lightweight aggregate with a particle size of 2~10 mm in mineralization supernatant, pre-soak for 30 minutes, then remove and drain until surface dry.

[0047] S101. Dry powder premixing: The pre-prepared cementitious components of solid waste, 120 parts of pretreated lightweight porous coal gangue aggregate, and 40 parts of aeolian sand with a particle size of 0.1~1.18 mm are put into a mixer and dry-mixed at a speed of 200 r / min for 3 min to obtain a uniform dry mixture.

[0048] S102. Adding liquid to form a slurry: Add mixing liquid (made by mixing water and mineralized supernatant at a volume ratio of 1:1) to the mixed dry materials, control the water-cement ratio (mass ratio of mixing liquid to cementitious component) to be 0.55, and add polycarboxylate superplasticizer (admixture) at 0.2% of the mass of cementitious component. Stir at 350 r / min for 5 min to obtain a slurry with good fluidity and uniformity.

[0049] S103. Adding reinforcing components: Add reinforcing components (mineralized modified waste fishing net fibers) to the slurry. The amount of reinforcing components is 0.4% of the mass of the cementitious components. Increase the speed of the mixer to 500 r / min and continue mixing for 8 min to ensure that the fibers are evenly dispersed, thus obtaining the all-solid waste lightweight aggregate grout.

[0050] Example 2

[0051] Preparation of the cementitious component: 35 parts of coal gangue powder, 45 parts of calcium carbide slag, and 18 parts of desulfurized gypsum were weighed out, passed through a 200-mesh sieve, and mixed evenly. Deionized water was sprayed into the mixture to adjust the moisture content to approximately 5%, and the mixture was pressed into test cakes. The test cakes were placed in a programmable temperature controlled electric furnace for staged calcination and activation: starting from 60°C, the temperature was increased to 900°C at a rate of 18°C / min, then increased to 1200°C at a rate of 6°C / min, and held at 1200°C for 45 min. Subsequent cooling, crushing, and ball milling steps were the same as in Example 1, yielding a cementitious component of all solid waste with a D50 of approximately 20 μm.

[0052] Preparation of reinforcing components:

[0053] Mineralization system: Calcium carbide slag is mixed with water to prepare a mineralization slurry with a solid content of 10%. Pure CO2 gas (100% by volume) is continuously introduced into the slurry, and a wet mineralization reaction is carried out at room temperature for 55 minutes to obtain a mineralization system containing fine calcium carbonate particles. The supernatant of the mineralization process can be collected at the same time.

[0054] Subsequently, waste fishing net fibers with a length of 12 mm were added to the mineralization system and stirred to allow calcium carbonate to nucleate heterogeneously on the fiber surface and deposit in situ. After the reaction was completed, the fibers were filtered to separate them and then surface-dried in an oven at 60°C to obtain mineralized modified waste fishing net fibers with a calcium carbonate deposition layer on the surface, which was the reinforcing component. The fiber weight gain was measured to be 1.5%.

[0055] Lightweight aggregate pretreatment: In this embodiment, steel slag aggregate (particle size 5~15 mm) is used as lightweight porous aggregate. The steel slag aggregate is immersed in the mineralization supernatant for 5 minutes and then drained until it is surface dry.

[0056] S201. Dry powder premixing: The pre-prepared cementitious components of solid waste, 80 parts of pretreated steel slag lightweight porous aggregate, and 60 parts of river sand with a particle size of 0.15~2.36 mm are put into a mixer and dry-mixed at a speed of 200 r / min for 2.5 min to obtain mixed dry material.

[0057] S202, Adding Liquid to Form Slurry: Add mixing liquid to the mixed dry materials (in this embodiment, pre-prepared mineralized slurry is used directly as part of the mixing liquid, mixed with water at a volume ratio of 1:1, controlling the total water-cement ratio to be 0.45), and add 0.1% polycarboxylate superplasticizer and 0.05% defoamer by mass of the gelling component. Stir at 350 r / min for 4 min to obtain the slurry.

[0058] S203, Adding reinforcing components: Add (mineralized modified waste fishing net fiber) to the slurry, with the amount of reinforcing components being 0.8% of the mass of the cementitious components. Increase the mixer speed to 500 r / min and continue mixing for 5 min to obtain all-solid waste lightweight aggregate grout.

[0059] Example 3

[0060] Preparation of cementitious components: 32 parts of coal gangue powder, 50 parts of carbide slag, and 22 parts of desulfurized gypsum were weighed out respectively. The preparation process was the same as in Example 1. The staged calcination activation was carried out as follows: the initial temperature was 90℃, which was increased to 900℃ at 12℃ / min; then increased to 1200℃ at 9℃ / min and held at that temperature for 55 min. A cementitious component with a D50 of approximately 18 μm was obtained.

[0061] Preparation of reinforcing components:

[0062] Mineralization system: Calcium carbide slag is mixed with water to prepare a mineralization slurry with a solid content of 25%. CO2 gas (volume fraction of 15%) is continuously introduced into the slurry, and a wet mineralization reaction is carried out at room temperature for 60 min to obtain a mineralization system containing fine calcium carbonate particles. The supernatant of the mineralization process can be collected at the same time.

[0063] Subsequently, waste fishing net fibers with a length of 9 mm were added to the mineralization system and stirred to allow calcium carbonate to nucleate heterogeneously on the fiber surface and deposit in situ. After the reaction was completed, the fibers were filtered to separate them and then surface-dried in an oven at 60°C to obtain mineralized modified waste fishing net fibers with a calcium carbonate deposition layer on the surface, which was the reinforcing component. The fiber weight gain was measured to be 8.0%.

[0064] Aggregate selection: No aggregate pretreatment is performed in this embodiment. 150 parts of lightweight coal gangue aggregate (particle size 8~20 mm) and 20 parts of aeolian sand are used directly.

[0065] S301, Dry powder premixing: The pre-prepared cementitious components of solid waste, 150 parts of lightweight coal gangue aggregate (particle size 8~20mm) and 20 parts of aeolian sand are put into a mixer and dry-mixed at a speed of 200 r / min for 3 min to obtain a uniform mixed dry material.

[0066] S302, Adding Liquid to Form a Slurry: Add mixing liquid (using pure water as the mixing liquid) to the mixed dry materials, controlling the water-to-binder ratio to be low at 0.38. Add 0.5% (by mass) of high-efficiency water-reducing agent and 0.3% (by mass) of water-retaining agent (hydroxypropyl methylcellulose) to the gelling components. Stir at 350 r / min for 5 min to obtain a high-consistency slurry.

[0067] S303, Adding reinforcing components: Add reinforcing components (mineralized modified waste fishing net fibers) to the slurry, using a high fiber content of 1.2%. Stir vigorously at 500 r / min for 8 min to ensure that the fibers are fully dispersed in the viscous slurry, and obtain all-solid waste lightweight aggregate grout.

[0068] Example 4

[0069] Preparation of gelling components: The proportions are the same as in Example 1, and the graded calcination and activation are the same as in Example 1 to obtain the gelling components.

[0070] Preparation of reinforcing components:

[0071] Mineralization system: Calcium carbide slag is mixed with water to prepare a mineralization slurry with a solid content of 30%. CO2 gas (volume fraction of 50%) is continuously introduced into the slurry, and a wet mineralization reaction is carried out at room temperature for 56 minutes to obtain a mineralization system containing fine calcium carbonate particles. The supernatant of the mineralization process can be collected at the same time.

[0072] Subsequently, waste fishing net fibers with a length of 6 mm were added to the mineralization system and stirred to allow calcium carbonate to nucleate heterogeneously on the fiber surface and deposit in situ. After the reaction was completed, the fibers were filtered to separate them and then surface-dried in an oven at 60°C to obtain mineralized modified waste fishing net fibers with a calcium carbonate deposition layer on the surface, which was the reinforcing component. The fiber weight gain was measured to be 0.6%.

[0073] Aggregate pretreatment: Immerse lightweight coal gangue aggregate with a particle size of 2~10 mm in mineralization supernatant, pre-soak for 15 minutes, then remove and drain until surface dry.

[0074] S401. Dry material mixing: 100 parts of pre-prepared gelling components, 100 parts of pre-treated aggregate, and 80 parts of aeolian sand are put into a mixer and dry-mixed at 200 r / min for 3 min to obtain a uniform dry mixture.

[0075] S402. Slurry Formation: The key to this embodiment is that the mixing liquid is entirely composed of mineralized slurry (undiluted), and the water-cement ratio is controlled to 0.50 by adjusting the amount added. No additives are added. The mixture is stirred at 350 r / min for 3 min to obtain the slurry.

[0076] S403. Adding reinforcing components: Add reinforcing components (mineralized modified waste fishing net fibers) to the slurry. The amount of reinforcing components is 0.08% of the mass of the cementitious components. Stir at 500 r / min for 9 min to ensure uniform fiber dispersion, thus obtaining the all-solid waste lightweight aggregate grout.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 1 is that the cementitious component is replaced with ordinary Portland cement.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Example 1 is that no mineralization modification is performed on the fibers; instead, an equal amount of waste fishing net fibers are used directly.

[0081] Comparative Example 3

[0082] The difference between this comparative example and Example 1 is that recycled fibers (i.e., reinforcing components) are not added.

[0083] The grouting materials obtained in Examples 1-4 and Comparative Examples 1-3 were subjected to performance tests, and the test standards and methods are as follows:

[0084] (1) Slump test: The test was conducted in accordance with GB / T50080-2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixture".

[0085] (2) Compressive strength and splitting tensile strength tests: The tests were conducted in accordance with GB / T50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete".

[0086] (3) Shrinkage test: The test shall be conducted in accordance with GB / T50082-2009 "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete".

[0087] The test results are as follows:

[0088] Table 1

[0089]

[0090] As shown in Table 1, compared with Example 1, the crushing value of steel slag in Example 2 is greater than that of coal gangue, resulting in a decrease in strength. Compared with Example 1, the high fiber content in Example 3 leads to a decrease in fluidity, a slight increase in strength, and a reduction in shrinkage.

[0091] Compared to Example 1, Comparative Example 2 shows that replacing the all-solid waste cementitious material with ordinary silicate cementitious material results in strength formation after 1 day, lacking the early strength and rapid hardening properties. Compared to Example 1, Comparative Example 2 demonstrates that the mineralization modification of the fiber enhances the bond between the fiber and the matrix, thereby increasing strength and reducing shrinkage.

[0092] See further Figure 3 The XRD pattern of the all-solid waste cementitious material prepared in Example 1 is shown.

[0093] The main component of the solid waste cementitious material is tetracalcium sulfoaluminate (Ca4Al). 16 O 12 It contains dicalcium silicate (Ca2SiO4) and a small amount of calcium sulfate (CaSO4). Ca4Al 16 O 12 SO4 has the characteristics of high activity, fast solidification and hardening speed, low alkalinity, and good low-temperature performance.

[0094] See Figure 4 and Figure 5 The XRD and TG-DSC diagrams of the grout prepared in Example 1 are shown.

[0095] The main hydration products of the grout are ettringite (AFt) and aluminum hydroxide (AH3). AFt rapidly forms in the early stages, exhibiting a needle-like or rod-shaped crystal morphology that interweaves to form a continuous spatial framework structure. AH3 precipitates in colloidal or microcrystalline form, uniformly filling the spaces between the AFt framework and the pores within the grout. These two components work synergistically to construct a stable and continuous three-dimensional network structure. Simultaneously, the XRD characteristic peak intensity of AFt continuously increases with age, indicating that the hydration reaction progresses, the amount of products generated increases, and the crystal structure gradually improves. Especially at 7 hours, its characteristic peak intensity reaches approximately 80% of the 28-day peak intensity, demonstrating that the active component in this invention can rapidly participate in the reaction in the early stages and generate a large amount of structural hydration products, thereby establishing a stable spatial support structure in a short time and achieving a significant early strength and rapid hardening effect. Furthermore, from... Figure 5 It can be seen that the mass loss rate of AFt and AH3 gradually decreases with increasing age, indicating that the structural stability of the hydration products is continuously enhanced, the porosity of the system decreases, and the structure tends to become more compact.

[0096] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.

Claims

1. A lightweight aggregate grouting material made entirely of solid waste, characterized in that, Includes cementitious components, aggregate components, reinforcing components, mixing liquid, and admixtures, among which: The cementitious components, by mass fraction, include 30-38 parts of pretreated coal gangue powder, 40-52 parts of calcium carbide slag, and 15-26 parts of desulfurized gypsum; The aggregate composition includes 50-250 parts of lightweight porous aggregate and 10-150 parts of fine aggregate; The reinforcing component is recycled fiber, and the dosage is 0.05~1.5% of the mass of the cementitious component. The recycled fiber is mineralized modified waste fishing net fiber, and its surface has a calcium carbonate deposit layer generated by wet mineralization of carbide slag and deposited in situ. The mixing liquid is a combination of water and one or more of the mineralization system products, wherein the mineralization system products are selected from mineralization supernatant or mineralization slurry; the mass ratio of the mixing liquid to the cementing component is (0.35~0.60):1; The admixture is one or more of water-reducing agents, water-retaining agents, and defoamers, and the dosage is 0 to 1.0% of the mass of the gelling component.

2. The all-solid-waste lightweight aggregate grouting material according to claim 1, characterized in that, The cementitious component is prepared by the following steps: coal gangue powder, carbide slag and desulfurized gypsum are passed through a 200-mesh sieve and mixed according to the formula to obtain a mixture; deionized water is added to the mixture to make it slightly moist and it is pressed into a test cake; the test cake is then placed in an electric furnace for graded calcination and activation; after being taken out of the furnace, it is rapidly cooled and then crushed, ball-milled and sieved to obtain the cementitious component, the D50 of which is 15~30 μm.

3. The all-solid-waste lightweight aggregate grouting material according to claim 2, characterized in that, The graded calcination activation is as follows: the initial temperature is 50~100℃, and the temperature is increased to 900℃ at a rate of 10~20℃ / min; then the temperature is increased to 1200℃ at a rate of 5~10℃ / min and held at this temperature for 40~60 min.

4. The all-solid-waste lightweight aggregate grouting material according to claim 1, characterized in that, The mineralized modified waste fishing net fiber is prepared by the following method: waste fishing net fiber is added to a mineralization system, so that calcium carbonate is heterogeneously nucleated and deposited in situ on the surface of the waste fishing net fiber, and then filtered and surface dried to obtain the mineralized modified waste fishing net fiber; the surface deposition layer of the mineralized modified waste fishing net fiber corresponds to a fiber weight gain rate of 0.5%~10%.

5. The all-solid-waste lightweight aggregate grouting material according to claim 4, characterized in that, The preparation method of the mineralization system includes the following steps: preparing a mineralized slurry with a solid content of 5% to 35% by mixing carbide slag and water, then introducing a CO2-containing gas with a volume fraction of 5% to 100% into the mineralized slurry, and carrying out a wet mineralization reaction for 45 to 60 minutes to obtain the mineralization system.

6. The all-solid-waste lightweight aggregate grouting material according to claim 1, characterized in that, The lightweight porous aggregate is coal gangue aggregate and / or steel slag aggregate with a particle size of 2-20 mm; the fine aggregate is river sand and / or aeolian sand with a particle size of 0.1-2.36 mm.

7. The all-solid-waste lightweight aggregate grouting material according to claim 5, characterized in that, The lightweight porous aggregate is obtained by pre-soaking in mineralization supernatant for 0.5 to 30 minutes and then surface drying. The mineralization supernatant is collected from the preparation process of the mineralization system.

8. A method for preparing a lightweight aggregate grouting material made entirely of solid waste as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Dry powder premixing: The cementitious component and aggregate component are stirred at 200 r / min for 2-3 min to obtain a mixed dry material; S2. Liquid addition to form slurry: The mixing liquid and admixture are added to the mixed dry material in S1, and stirred at 350 r / min for 3-5 min to obtain a slurry; S3. Adding reinforcing components: The reinforcing components are added to the slurry in S2, and stirred at 500 r / min for 5-8 min to obtain the all-solid waste lightweight aggregate grouting material.

9. The application of a solid waste lightweight aggregate grout as described in any one of claims 1 to 7 in roadbed backfilling, bridge abutment backfilling, or foundation reinforcement projects.

10. The application of mineralized modified recycled fiber as an interface reinforcement component in all-solid waste-based grouting materials, characterized in that, The mineralized modified recycled fiber is a waste fishing net fiber with a calcium carbonate layer deposited in situ by wet mineralization of carbide slag on its surface, which is used to improve the post-cracking load-bearing capacity and toughness of the grout.

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