A kind of fluid filling material and preparation method thereof

Abstract

The invention discloses a fluidized filling material and a preparation method thereof, belonging to the technical field of building materials. The fluidized filling material comprises the following raw material components and their weight parts: 85-95 parts of construction waste recycled redundant soil slurry, 5-15 parts of water plant tailings slurry, 40-60 parts of low-quality construction waste recycled aggregate, 5-10 parts of granulated blast furnace slag powder, 3-6 parts of asbestos-free mineral fiber, 1-4 parts of cement, 1-2 parts of industrial by-product gypsum, 0.3-1 parts of bentonite, and 0.5-1.5 parts of water reducer, which are prepared by mixing. The fluidized filling material of the invention has excellent and stable performance, realizes the green resource utilization of construction waste and water plant tailings, and solves the problems of excessively high treatment costs and environmental pollution that may be caused by construction waste and water plant tailings.

Description

Technical Field

[0001] The invention relates to a fluid filling material and a preparation method thereof, belonging to the technical field of building materials. Background Art

[0002] There are many disadvantages in the traditional backfilling method. The first is the high construction cost. The traditional method requires a large number of manual labor for layered compaction, which consumes a lot of human resources, and requires frequent adjustment and maintenance of compaction equipment, which increases the construction cost. In addition, the transportation and processing of bare soil or gray soil as backfill materials will also incur additional expenses. In terms of construction efficiency, large-scale compaction equipment is difficult to use in narrow construction spaces and complex terrain conditions, and can only rely on small equipment, resulting in reduced compaction efficiency. The cumbersome steps of layered backfilling also slow down the overall construction progress. Construction difficulty is also an important issue. Especially when the backfill depth is large or the compaction quality is required to be high, small compaction equipment is difficult to meet the needs, and it is difficult to ensure the uniformity and density of the backfill soil. Settlement and other problems are prone to occur, which increases the complexity of construction. In summary, the traditional backfilling method has problems such as high cost investment, low construction efficiency and complex construction difficulty. It is urgent to find new technical means to solve these challenges.

[0003] At the same time, in the process of producing recycled aggregates, there is often the problem of the generation of redundant soil from construction waste. These redundant soils are mainly derived from process wastes generated during the screening, cleaning and processing of construction waste. If they are not processed for resource utilization, it will cause the problem of waste of site, and as the stacking time increases, the moisture content of the redundant soil decreases, and environmental pollution problems such as dust will also occur; water plants will also produce a large amount of tailings in the process of producing drinking water. Its composition is complex, including raw water suspended matter, colloids, microorganisms, organic matter and added water purification agents. Traditional landfill treatment methods not only occupy a large amount of precious land resources, but also may cause environmental pollution and threaten groundwater quality. Considering the large fluctuations in the moisture content of different batches of recycled redundant soil and the problem of safe disposal of tailings from water plants, it is urgent to find more environmentally friendly and efficient new technologies to achieve resource utilization and minimize adverse effects on the environment.

[0004] Fluidized backfill is a new type of backfill material that is made of soil or industrial and mining waste as the base material, mixed with an appropriate amount of cementitious materials, necessary additives and water, and fully mixed in a mixing device. This material has excellent fluidity and filling capacity, can be transported or pumped through pipes, can be self-compacted during construction, and exhibits certain strength and other required engineering properties after solidification and hardening. Fluidized backfill can not only effectively cover complex spaces and improve foundation stability and bearing capacity, but also has a simple, environmentally friendly and efficient construction process, which can significantly reduce engineering costs and improve construction efficiency and accuracy. It is a good narrow foundation pit fertilizer trough filling material.

[0005] In view of the above situation, it is necessary to develop a fluid filling material for recycling redundant soil from construction waste and tailings of water plants; it can not only reduce resource consumption and production costs, but also effectively reduce treatment costs and improve the ecological environment, while greatly improving resource utilization efficiency and promoting sustainable development. Summary of the invention

[0006] In order to address at least one problem existing in the above-mentioned prior art, the present invention provides a fluidized fill material and a method for preparing the same. The fluidized fill material uses construction waste and water plant tailings as a base material, and can obtain a fluidized fill material with excellent performance and stability, thereby realizing the green resource utilization of construction waste and water plant tailings, and solving the problems of excessively high treatment costs and environmental pollution that may be caused by construction waste and water plant tailings.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a fluid filling material, comprising the following raw material components and their weight proportions: 85-95 parts of construction waste recycled redundant soil slurry, 5-15 parts of water plant tailings slurry, 40-60 parts of low-quality construction waste recycled aggregate, 5-10 parts of granulated blast furnace slag powder, 3-6 parts of asbestos-free mineral fiber, 1-4 parts of cement, 1-2 parts of industrial by-product gypsum, 0.3-1 parts of bentonite, and 0.5-1.5 parts of water reducer.

[0008] Preferably, the weight of the low-quality construction waste recycled aggregate accounts for 40.0-60.0% of the sum of the weight of the construction waste recycled redundant soil slurry and the water plant tailings slurry.

[0009] Preferably, the sum of the weights of the granulated blast furnace slag powder and the asbestos-free mineral fiber accounts for 8.5-16.0% of the sum of the weights of the construction waste recycled redundant soil slurry and the waterworks tailings slurry.

[0010] Preferably, the weight of the asbestos-free mineral fiber accounts for 5.5-13.0% of the weight of the low-quality construction waste recycled aggregate.

[0011] Preferably, the wet density of the construction waste recycled redundant soil slurry is 1.3-1.4 t / m3 .

[0012] Preferably, the construction waste recycled redundant soil slurry is prepared from construction waste recycled redundant soil, the construction waste recycled redundant soil is a solid or semi-solid soil sample, and the percentage of moisture in the construction waste recycled redundant soil to the dry mass of the soil sample is 20-45%.

[0013] Preferably, the wet density of the waterworks tailings slurry is 1.11-1.15 t / m 3 .

[0014] Preferably, the waterworks tailings slurry is prepared from waterworks tailings, the waterworks tailings is a semi-solid soil sample, and the organic matter content of the waterworks tailings is greater than 10%, and the percentage of water in the waterworks tailings to the dry mass of the soil sample is 200-400%.

[0015] Preferably, the low-quality construction waste recycled aggregate is a mixture of original inorganic non-metallic materials with a particle size less than 10 mm produced by multi-stage sorting of construction waste; the mixture of original inorganic non-metallic materials includes waste bricks, tiles, porcelain, waste concrete, waste stone, concrete blocks and aerated blocks, etc.

[0016] Preferably, the asbestos-free mineral fiber has a particle size of 3-5 μm and a length of 1-2 mm.

[0017] Preferably, the granulated blast furnace slag powder is S95 grade granulated blast furnace slag powder.

[0018] Preferably, the cement is ordinary Portland cement, and the strength grade is not less than 42.5.

[0019] Preferably, the industrial by-product gypsum is one or more of desulfurized gypsum, phosphogypsum and fluorinated gypsum, preferably desulfurized gypsum.

[0020] Preferably, the bentonite is sodium-based bentonite or calcium-based bentonite, with a particle size of ≥200 mesh, preferably calcium-based bentonite.

[0021] Preferably, the water reducer is one of a polycarboxylic acid water reducer, a melamine water reducer or a composite water reducer.

[0022] A method for preparing a fluid filling material, the preparation method comprising the following steps:

[0023] (1) The wet density of the slurry made from the redundant soil of recycled construction waste is controlled by the ratio of the mixing water to the mass of the redundant soil of recycled construction waste, and is calculated according to formula (1):

[0024] (1)

[0025] Where: y1 The wet density of redundant soil slurry recycled from construction waste, in t / m 3 ;

[0026] ω 1 It is the percentage of water content in redundant soil regenerated from construction waste to the dry mass of soil sample;

[0027] x 1 It is the ratio of the mass of mixing water to the mass of redundant soil from construction waste and recycled waste;

[0028] (2) For slurrying of tailings from waterworks, the wet density is controlled by the ratio of the mixing water to the mass of tailings from waterworks, and is calculated according to formula (2):

[0029] (2)

[0030] Where: y 2 is the wet density of tailings slurry from waterworks, in t / m 3 ;

[0031] ω 2 It is the percentage of water content in the tail mud of the waterworks to the dry mass of the soil sample;

[0032] x 2 It is the mass ratio of mixing water to tailings sludge from waterworks;

[0033] (3) After the two types of mud are prepared, they are weighed according to the above weight parts through a metering system and enter a pre-homogenization tank for homogenization treatment to obtain a homogenized mixed mud;

[0034] (4) Add low-quality construction waste recycled aggregate, granulated blast furnace slag powder, asbestos-free mineral fiber, cement, industrial by-product gypsum, bentonite and water reducer according to the above weight parts into the homogenized mixed mud and mix and stir until evenly mixed to obtain a finished fluid filling material.

[0035] Preferably, the redundant soil regenerated from construction waste is a solid or semi-solid soil sample. 1 It is 20~45%.

[0036] Preferably, the waterworks tailings are semi-solid soil samples, and the organic matter content of the waterworks tailings is greater than 10%. 2 It is 200~400%.

[0037] The beneficial effects of the present invention are as follows: 1. The fluidized filling material of the present invention uses construction waste and water plant tailings as base materials, realizes the green resource utilization of construction waste and water plant tailings, and solves the problems of excessively high treatment costs and environmental pollution that may be caused by construction waste and water plant tailings; 2. In the case that the raw material moisture content of redundant soil of construction waste and water plant tailings is unstable, a fluidized filling material with stable and excellent performance is obtained; 3. Compared with traditional fluidized filling materials that use cement as a solidifying material, the fluidized filling material of the present invention has lower cost and better performance; 4. The fluidized filling material of the present invention does not need to pre-treat the water plant tailings, and can be directly used to prepare the fluidized filling material, making the tailings disposal steps simpler and the cost lower. DETAILED DESCRIPTION

[0038] The following is a clear and complete description of the technical solutions in the implementation of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents, instruments, and components used, they are all conventional products that can be purchased commercially.

[0039] The invention provides a fluid filling material, comprising the following raw material components and their weight proportions: 85-95 parts of construction waste recycled redundant soil slurry, 5-15 parts of water plant tailings slurry, 40-60 parts of low-quality construction waste recycled aggregate, 5-10 parts of granulated blast furnace slag powder, 3-6 parts of asbestos-free mineral fiber, 1-4 parts of cement, 1-2 parts of industrial by-product gypsum, 0.3-1 parts of bentonite and 0.5-1.5 parts of water reducer.

[0040] The present invention further comprises that the weight of the low-quality construction waste recycled aggregate accounts for 40-60% of the sum of the weight of the construction waste recycled redundant soil slurry and the waterworks tailings slurry.

[0041] The present invention further comprises that the sum of the weight of the granulated blast furnace slag powder and the asbestos-free mineral fiber accounts for 8.5-16.0% of the sum of the weight of the redundant soil slurry recycled from construction waste and the tailings slurry of the waterworks.

[0042] The present invention further comprises that the weight of the asbestos-free mineral fiber accounts for 6.0-13.0% of the weight of the recycled aggregate from low-quality construction waste.

[0043] The present invention further comprises that the wet density of the redundant soil slurry regenerated from construction waste is 1.3-1.4 t / m 3 .

[0044] The present invention further comprises that the wet density of the waterworks tailings slurry is 1.11-1.15 t / m 3 .

[0045] The present invention further states that the low-quality construction waste recycled aggregate is a mixture of original inorganic non-metallic materials with a particle size less than 10 mm produced by multi-stage sorting of construction waste; the mixture of original inorganic non-metallic materials includes waste bricks, tiles, porcelain, waste concrete, waste stone, concrete blocks and aerated blocks, etc.

[0046] In the present invention, the asbestos-free mineral fiber has a particle size of 3-5 μm and a length of 1-2 mm.

[0047] Furthermore, in the present invention, the granulated blast furnace slag powder is S95 grade granulated blast furnace slag powder.

[0048] Furthermore, in the present invention, the cement is ordinary Portland cement, and the strength grade is not less than 42.5.

[0049] In the present invention, the industrial by-product gypsum is one or more of desulfurized gypsum, phosphogypsum and fluorinated gypsum, preferably desulfurized gypsum.

[0050] In the present invention, the bentonite is sodium-based bentonite or calcium-based bentonite, and the particle size is ≥ 200 mesh, preferably calcium-based bentonite.

[0051] In the present invention, the water reducer is one of a polycarboxylic acid water reducer, a melamine water reducer or a composite water reducer, preferably a polycarboxylic acid water reducer.

[0052] The present invention also provides a method for preparing a fluid filling material, the preparation method comprising the following steps:

[0053] (1) The wet density of the slurry made from the redundant soil of recycled construction waste is controlled by the ratio of the mixing water to the mass of the redundant soil of recycled construction waste, and is calculated according to formula (1):

[0054] (1)

[0055] Where: y 1 The wet density of redundant soil slurry recycled from construction waste, in t / m 3 ;

[0056] ω 1 is the percentage of moisture in the redundant soil recycled from construction waste to the dry mass of the soil sample, ω 1 20~45%;

[0057] x 1 It is the ratio of the mass of mixing water to the mass of redundant soil from construction waste and recycled waste;

[0058] (2) For slurrying of tailings from waterworks, the wet density is controlled by the ratio of the mixing water to the mass of tailings from waterworks, and is calculated according to formula (2):

[0059] (2)

[0060] Where: y 2 is the wet density of tailings slurry from waterworks, in t / m 3 ;

[0061] ω 2 is the percentage of water in the tail mud of the water plant to the dry mass of the soil sample, ω 2 200~400%;

[0062] x 2 It is the mass ratio of mixing water to tailings sludge from waterworks;

[0063] (3) After the two types of mud are prepared, they are weighed according to the above weight parts through a metering system and enter a pre-homogenization tank for homogenization treatment to obtain a homogenized mixed mud;

[0064] (4) Add low-quality construction waste recycled aggregate, granulated blast furnace slag powder, asbestos-free mineral fiber, cement, industrial by-product gypsum, bentonite and water reducer according to the above weight parts into the homogenized mixed mud and mix and stir until evenly mixed to obtain a finished fluid filling material.

[0065] It should be noted that in equations (1) and (2), when the wet density y 1 is the required constant value, x 1 With ω 1 When the wet density y 2 is the required constant value, x 2 With ω 2的 Change and change.

[0066] Example

[0067] In the embodiments, the wet density of the redundant soil slurry recycled from construction waste in embodiments 1 to 10 and embodiments 13 to 15 is 1.3 t / m 3 In Example 11, the wet density is 1.4 t / m 3 In Example 12, the wet density is 1.3 t / m 3 The wet density of the waterworks tailings slurry used in Examples 1 to 10 and 13 to 15 was 1.11 t / m 3 In Example 11, the wet density is 1.13 t / m 3 In Example 12, the wet density is 1.15 t / m 3; The low-quality construction waste recycled aggregate used in Examples 1 to 15 is an original inorganic non-metallic material mixture with a particle size of less than 10 mm produced by multi-stage sorting of construction waste; the granulated blast furnace slag powder used in Examples 1 to 15 is S95 grade slag powder that meets the technical requirements of GB / T 18046-2008 "Granulated blast furnace slag powder for cement and concrete"; the particle size of the asbestos-free mineral fiber used is 3 to 5 μm and the length is 1 to 2 mm. The cement used in Examples 1 to 15 is PO 42.5 grade ordinary Portland cement; the industrial by-product gypsum used in Examples 1 to 14 is desulfurized gypsum dihydrate, and in Example 15 is phosphogypsum; the bentonite used in Examples 1 to 12 and 14 to 15 is calcium-based bentonite, and in Example 13 is sodium-based bentonite, and the particle fineness of the bentonite in Examples 1 to 15 is ≥ 200 mesh; the water reducer used in Examples 1 to 13 and 15 is polycarboxylate water reducer, and in Example 14 is melamine water reducer; the weight parts of each component in the embodiment are shown in Table 1, and the fluidized filling material is obtained according to the following preparation method:

[0068] (1) The wet density of the slurry made from the redundant soil of recycled construction waste is controlled by the ratio of the mixing water to the mass of the redundant soil of recycled construction waste, and is calculated according to formula (1):

[0069] (1)

[0070] Where: y 1 The wet density of redundant soil slurry recycled from construction waste, in t / m 3 ;

[0071] ω 1 is the percentage of moisture in the redundant soil recycled from construction waste to the dry mass of the soil sample, ω 1 20~45%;

[0072] x 1 It is the ratio of the mass of mixing water to the mass of redundant soil from construction waste and recycled waste;

[0073] (2) For slurrying of tailings from waterworks, the wet density is controlled by the ratio of the mixing water to the mass of tailings from waterworks, and is calculated according to formula (2):

[0074] (2)

[0075] Where: y 2 is the wet density of tailings slurry from waterworks, in t / m 3 ;

[0076] ω 2 is the percentage of water in the tail mud of the water plant to the dry mass of the soil sample, ω 2 200~400%;

[0077] x 2 It is the mass ratio of mixing water to tailings sludge from waterworks;

[0078] (3) After the two types of mud are prepared, they are weighed by a metering system according to the weight parts shown in Table 1 and then enter a pre-homogenization tank for homogenization to obtain a homogenized mixed mud;

[0079] (4) Add low-quality construction waste recycled aggregate, granulated blast furnace slag powder, asbestos-free mineral fiber, cement, industrial by-product gypsum, bentonite, and water reducing agent according to the weight parts shown in Table 1 into the homogenized mixed mud and mix and stir until evenly mixed to obtain a finished fluid filling material;

[0080] Among them, choose y 1 1.3t / m 3 ,ω 1 is 45%, x 1 is 0.6789:1; select y 1 1.35t / m 3 ,ω 1 is 30%, x 1 is 0.580:1; select y 1 1.4t / m 3 ,ω 1 is 20%, x 1 is 0.5068:1;

[0081] Select y 2 1.11t / m 3 ,ω 2 is 200%, x 2 is 0.8165:1; select y 2 1.13t / m 3 ,ω 2 is 400%, x 2 is 0.2699:1; select y 2 1.15t / m 3 ,ω 2 is 300%, x 2 It is 0.2529:1.

[0082] Table 1 Weight parts of each component in the examples

[0083]

[0084] Note that in the table: Mud 1 represents redundant soil slurry recycled from construction waste, Mud 2 represents tailings slurry from waterworks, recycled aggregate represents recycled aggregate from low-quality construction waste, slag powder represents granulated blast furnace slag powder; Fiber represents asbestos-free mineral fiber.

[0085] Comparative Example

[0086] In the comparative examples, the wet density of the redundant soil slurry recycled from construction waste in comparative examples 1 to 13 is 1.3 t / m 3 The wet density of the waterworks tailings slurry used in Comparative Examples 1 to 13 is 1.15 t / m 3 The low-quality recycled aggregate from construction waste is a mixture of original inorganic non-metallic materials produced by multi-stage sorting of construction waste, with a particle size of less than 10 mm in Comparative Examples 1 to 10 and 12 to 13, and a particle size of greater than 10 mm and less than 50 mm in Comparative Example 11; the granulated blast furnace slag powder used is S95 grade slag powder that meets the technical requirements of GB / T18046-2008 "Granulated blast furnace slag powder for cement and concrete"; the particle size of the asbestos-free mineral fiber in Comparative Examples 1 to 11 and 13 is 3 to 5 μm and the length is 1 to 2 mm, and the particle size in Comparative Example 12 is 5 to 8 μm and the length is 2 to 3 mm; the cement used is PO 42.5 grade ordinary Portland cement; the industrial by-product gypsum used in Comparative Examples 1 to 13 is desulfurized gypsum dihydrate; the bentonite used in Comparative Examples 1 to 13 is calcium-based bentonite, and the particle fineness in Comparative Examples 1 to 12 is greater than 200 mesh, and the particle fineness in Comparative Example 13 is less than 200 mesh and greater than 100 mesh; the water reducer used in Comparative Examples 1 to 13 is a polycarboxylic acid water reducer; the weight parts of each component in the comparative example are shown in Table 2, and the fluidized filling material is obtained according to the following preparation method:

[0087] (1) The wet density of the slurry made from the redundant soil of recycled construction waste is controlled by the ratio of the mixing water to the mass of the redundant soil of recycled construction waste, and is calculated according to formula (1):

[0088] (1)

[0089] Where: y 1 The wet density of redundant soil slurry recycled from construction waste, in t / m 3 ;

[0090] ω 1 is the percentage of moisture in the redundant soil recycled from construction waste to the dry mass of the soil sample, ω 1 20~45%;

[0091] x 1 It is the ratio of the mass of mixing water to the mass of redundant soil from construction waste and recycled waste;

[0092] (2) For slurrying of tailings from waterworks, the wet density is controlled by the ratio of the mixing water to the mass of tailings from waterworks, and is calculated according to formula (2):

[0093] (2)

[0094] Where: y 2 is the wet density of tailings slurry from waterworks, in t / m 3 ;

[0095] ω 2 is the percentage of water in the tail mud of the water plant to the dry mass of the soil sample, ω 2 200~400%;

[0096] x 2 It is the mass ratio of mixing water to tailings sludge from waterworks;

[0097] (3) After the two types of mud are prepared, they are weighed according to the above weight parts through a metering system and enter a pre-homogenization tank for homogenization treatment to obtain a homogenized mixed mud;

[0098] (4) Adding low-quality construction waste recycled aggregate, granulated blast furnace slag powder, asbestos-free mineral fiber, cement, industrial by-product gypsum, bentonite, and water reducing agent according to the above weight parts into the homogenized mixed mud and mixing and stirring until evenly mixed to obtain a finished fluid filling material;

[0099] Among them, choose y 1 1.3t / m 3 ,ω 1 is 45%, x 1 is 0.6789:1; select y 2 1.11t / m 3 ,ω 2 is 200%, x 2 It is 0.8165:1.

[0100] Table 2 Weight parts of each component in comparative example

[0101]

[0102] Note that in the table: Mud 1 represents redundant soil slurry recycled from construction waste, Mud 2 represents tailings slurry from waterworks, recycled aggregate represents recycled aggregate from low-quality construction waste, slag powder represents granulated blast furnace slag powder; Fiber represents asbestos-free mineral fiber.

[0103] The fluidized filling materials prepared in the above Examples 1 to 15 and the fluidized filling materials in Comparative Examples 1 to 13 were tested for wet density, expansion and compressive strength in accordance with the Technical Standard for Backfill Engineering of Fluidized Fill Materials (T / CMEA 32-2023). The test results are shown in Table 3.

[0104] Table 3 Performance test

[0105]

[0106] It can be seen from Tables 1 to 3 above that the fluidized filling materials prepared in Examples 1 to 15 of the present invention and the fluidized filling materials prepared in Comparative Examples 1, 3 to 5, 7 and 9 all meet the performance requirements of the "Technical Standard for Backfill Engineering of Fluidized Fill Materials" (T / CMEA 32-2023); however, compared with Comparative Examples 1, 3 to 5, 7 and 9, the fluidized filling materials prepared in Examples 1 to 15 have an expansion degree of 260 to 310 mm and a 28d compressive strength of 1.15 to 2.21 MPa, and have the characteristics of excellent flowability and high compressive strength, etc., and are a better narrow foundation pit fertilizer trough filling material.

[0107] Compared with Example 6, Comparative Example 1 lacks gypsum, and the wet density, expansion and 28d compressive strength of the fluid filling material are all reduced; Comparative Example 2 lacks granulated blast furnace slag powder, and the wet density and 28d compressive strength of the fluid filling material are all reduced, the expansion is 210mm, and the fluidity can not meet the "Technical Standard for Backfill Engineering of Fluid Filling Material" (T / CMEA 32-2023), in comparative example 3, there is a lack of asbestos-free mineral fiber, and the wet density, expansion and 28d compressive strength of the fluidized filling material are all reduced. In comparative example 4, there is a lack of gypsum and granulated blast furnace slag powder, and the weight of cement is increased, and the wet density, expansion and 28d compressive strength of the fluidized filling material are all reduced, and the reduction in the 28d compressive strength is relatively large, indicating that gypsum, granulated blast furnace slag powder, and asbestos-free mineral fiber in the construction waste recycled redundant soil slurry and water plant tailings slurry synergize with low-quality construction waste recycled aggregate, cement, bentonite, and water reducer, so that the fluidized filling material of the present invention has higher wet density, excellent specific flowability, high compressive strength and the like, and can be used in narrow foundation pit fertilizer troughs.

[0108] Compared with Example 9, the weight of the low-quality construction waste recycled aggregate in Comparative Example 5 accounts for 39.1% of the sum of the weight of the construction waste recycled redundant soil slurry and the water plant tailings slurry, which is lower than 40%. The wet density of the fluid filling material is 1384 kg / m 3, the wet density cannot meet the "Technical Standard for Backfill Engineering of Flowing Fill Materials" (T / CMEA 32-2023), and the 28d compressive strength is reduced; compared with Example 10, the weight of low-quality construction waste recycled aggregate in Comparative Example 6 accounts for 61.1% of the sum of the weight of construction waste recycled redundant soil slurry and water plant tailings slurry, which is higher than 60%, the 28d compressive strength of the flowable fill material is reduced, the expansion is 215mm, and the fluidity cannot meet the "Technical Standard for Backfill Engineering of Flowing Fill Materials" (T / CMEA 32-2023), in Example 7, the sum of the weight of granulated blast furnace slag powder and asbestos-free mineral fiber accounts for 7.8% of the sum of the weight of redundant soil slurry from construction waste recycling and tailings slurry from water plant, which is lower than 8.5%, and the expansion degree and 28d compressive strength of the fluidized filling material are reduced. In Example 8, the sum of the weight of granulated blast furnace slag powder and asbestos-free mineral fiber accounts for 16.7% of the sum of the weight of redundant soil slurry from construction waste recycling and tailings slurry from water plant, which is higher than 16.05%, and the 28d compressive strength of the fluidized filling material is reduced, the expansion degree is 210mm, and the fluidity cannot meet the "Technical Standard for Backfill Engineering of Fluidized Filling Material" (T / CMEA32-2023). In Example 10, the weight of asbestos-free mineral fiber accounts for 5.5% of the weight of low-quality recycled aggregate from construction waste, which is lower than 6.0%, and the wet density of the fluidized filling material is 1376kg / m 3 , the wet density cannot meet the "Technical Standard for Backfill Engineering of Fluid Filling Materials" (T / CMEA 32-2023), and the 28d compressive strength is also reduced; compared with Example 6, the weight of asbestos-free mineral fiber in Comparative Example 9 accounts for 13.3% of the weight of low-quality construction waste recycled aggregate, which is higher than 13%. The 28d compressive strength of the fluid filling material is 0.75Mpa, which is a large decrease, indicating that the weight of low-quality construction waste recycled aggregate accounts for 40-60% of the sum of the weight of construction waste recycled redundant soil slurry and water plant tailings slurry, and the weight of granulated blast furnace slag powder and asbestos-free mineral fiber is 0.75Mpa. The sum of the weight of recycled redundant soil slurry from construction waste and water plant tailings slurry accounts for 8.5~16.0% of the total weight of the slurry, and the weight of asbestos-free mineral fiber accounts for 6.0~13.0% of the weight of low-quality recycled aggregate from construction waste. The proportions of low-quality recycled aggregate from construction waste, granulated blast furnace slag powder, asbestos-free mineral fiber, recycled redundant soil slurry from construction waste, and water plant tailings slurry are suitable for each other, which can make the fluid filling material have high levels of wet density, expansion degree and 28d compressive strength at the same time.

[0109] Compared with Example 4, the particle size of the low-quality construction waste recycled aggregate in Comparative Example 11 is greater than 10 mm and less than 50 mm, the particle size of the asbestos-free mineral fiber in Comparative Example 12 is 5-8 μm and the length is 2-3 mm, and the particle fineness of the low-quality construction waste recycled aggregate in Comparative Example 13 is 100-200 mesh, which affects the wet density, expansion and 28d compressive strength of the fluidized fill material. The wet density cannot meet the "Technical Standard for Backfill Engineering of Fluidized Fill Material" (T / CMEA 32-2023), and the expansion and 28d compressive strength are reduced.

[0110] In summary, the fluidized filling materials prepared in Examples 1 to 15 of the present invention use construction waste and water plant tailings as base materials, and obtain fluidized filling materials with excellent flow properties, high compressive strength and stability through the synergistic effect of gypsum, granulated blast furnace slag powder, asbestos-free mineral fiber, low-quality construction waste recycled aggregate, cement, bentonite and water reducer. It is a better narrow foundation pit fertilizer trough filling material, and also realizes the green resource utilization of construction waste and water plant tailings, and solves the problems of excessively high treatment costs and environmental pollution that may be caused by construction waste and water plant tailings.

[0111] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit and essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0112] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A fluid filling material, characterized in that: The raw material components include the following and their weight parts: 85-95 parts of construction waste recycled redundant soil slurry, 5-15 parts of water plant tailings slurry, 40-60 parts of low-quality construction waste recycled aggregate, 5-10 parts of granulated blast furnace slag powder, 3-6 parts of asbestos-free mineral fiber, 1-4 parts of cement, 1-2 parts of industrial by-product gypsum, 0.3-1 parts of bentonite, and 0.5-1.5 parts of water reducer; The weight of the low-quality construction waste recycled aggregate accounts for 40.0-60.0% of the sum of the weight of the construction waste recycled redundant soil slurry and the water plant tailings slurry; The sum of the weight of the granulated blast furnace slag powder and the asbestos-free mineral fiber accounts for 8.5-16.0% of the sum of the weight of the redundant soil slurry recycled from construction waste and the tailings slurry of the waterworks; The weight of the asbestos-free mineral fiber accounts for 5.5-13.0% of the weight of the low-quality construction waste recycled aggregate.

2. A fluid filling material according to claim 1, characterized in that: The wet density of the construction waste recycled redundant soil slurry is 1.3-1.4 t / m 3 .

3. A fluid filling material according to claim 1, characterized in that: The wet density of the waterworks tailings slurry is 1.11-1.15 t / m 3 .

4. A fluid filling material according to claim 1, characterized in that: The low-quality recycled aggregate from construction waste is a mixture of original inorganic non-metallic materials with a particle size of less than 10 mm produced by multi-stage sorting of construction waste; the original mixture of inorganic non-metallic materials includes waste bricks, tiles, porcelain, waste concrete, waste stone, concrete blocks and aerated blocks; the particle size of the asbestos-free mineral fiber is 3~5μm, and the length is 1~2mm; the granulated blast furnace slag powder is S95 grade granulated blast furnace slag powder; the cement is ordinary Portland cement, and the strength grade is not less than 42.5; the industrial by-product gypsum is one or more of desulfurized gypsum, phosphogypsum and fluorinated gypsum; the bentonite is sodium-based bentonite or calcium-based bentonite, and the particle fineness is ≥200 mesh; the water reducer is one of polycarboxylic acid water reducer, melamine water reducer or composite water reducer.

5. A method for preparing the fluid filling material according to claim 1, characterized in that: The preparation method comprises the following steps: (1) The wet density of the slurry made from the redundant soil of recycled construction waste is controlled by the ratio of the mixing water to the mass of the redundant soil of recycled construction waste, and is calculated according to formula (1): （1） Where: y1 is the wet density of redundant soil slurry from construction waste, unit: t / m 3 ; ω1 is the percentage of water in the redundant soil recycled from construction waste to the dry mass of the soil sample; x1 is the ratio of the mass of mixing water to the redundant soil of construction waste recycled waste; (2) For slurrying of tailings from waterworks, the wet density is controlled by the ratio of the mixing water to the mass of tailings from waterworks, and is calculated according to formula (2): （2） Where: y2 is the wet density of tailings slurry from waterworks, unit is t / m 3 ; ω2 is the percentage of water in the tail mud of the waterworks to the dry mass of the soil sample; x2 is the mass ratio of mixing water to tailings sludge from waterworks; (3) Weighing the two slurries according to the above weight proportions and placing them into a pre-homogenizing tank for homogenization to obtain a homogenized mixed slurry; (4) Add low-quality construction waste recycled aggregate, granulated blast furnace slag powder, asbestos-free mineral fiber, cement, industrial by-product gypsum, bentonite and water reducer according to the above weight parts into the homogenized mixed mud and mix and stir until evenly mixed to obtain a finished fluid filling material.

6. The method for preparing the fluidized filling material according to claim 5, characterized in that: The redundant soil regenerated from construction waste is a solid or semi-solid soil sample, and ω1 is 20-45%.

7. The method for preparing the fluidized filling material according to claim 5, characterized in that: The waterworks tailings sludge is a semi-solid soil sample, and the organic matter content of the waterworks tailings sludge is greater than 10%, and ω2 is 200-400%.

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