Waste pipeline filling material, preparation method and application method

Abstract

The invention discloses a waste pipeline filling material, a preparation method and an application method, the waste pipeline filling material comprises a composite waste curing agent and mucky soft soil; the composite waste curing agent is formed by compounding dry powder and water; the dry powder comprises slag powder, carbide slag and desulfurized gypsum. The waste pipeline filling material disclosed by the invention is prepared by completely adopting the solid wastes, namely the slag powder, the carbide slag and the desulfurized gypsum as the curing agent to cure the sludge soft soil, has the advantages of wide raw material source, simplicity in preparation, high strength, low cost and the like, can fully recycle the solid wastes, and is low in energy consumption, low in emission and suitable for industrial production. And urban waste pipelines can be effectively filled, surface collapse accidents caused by structural damage of the urban waste pipelines are avoided, and positive significance is achieved for the ecological environment and urban development.

Description

Technical Field

[0001] The invention relates to the field of building materials, and in particular to a waste pipe filling material, a preparation method and an application method. Background Art

[0002] As my country's urbanization process continues to advance, underground pipelines have been widely used in many fields, among which water pipelines are mostly in urban underground pipeline networks. According to data from the National Bureau of Statistics, the length of water supply pipelines in cities across the country is currently 1.103 million kilometers, and the length of drainage pipelines is 913,500 kilometers. However, when underground pipelines reach their service life, pipes begin to enter a high-incidence period of accidents due to corrosion, aging, deformation and other problems. According to the "2022 National Underground Pipeline Accident Statistical Analysis Report", pipeline pavement collapse accidents have increased from 106 to 347. In 2021 alone, 1,723 underground pipeline-related accidents occurred, causing nearly 400 casualties. There is a very high potential risk of ground collapse accidents caused by structural damage to abandoned pipelines. In recent years, due to the frequent occurrence of ground collapse accidents caused by pipeline structural damage, abandoned urban pipelines have become an obstacle to urban development, not only becoming a safety hazard for surrounding buildings, but also endangering people's lives. Therefore, how to deal with abandoned urban pipelines is a major challenge facing the municipal industry today.

[0003] In addition, with the rapid development of the economy, the annual output of solid waste in my country is increasing day by day. According to statistics, the total amount of slag powder produced in my country in 2021 will exceed 110 million tons, the desulfurization gypsum produced after flue gas desulfurization in thermal power plants will exceed 80 million tons, and the waste residue produced after hydrolysis of calcium carbide to obtain acetylene gas - the annual output of calcium carbide slag will exceed 30 million tons. These solid wastes have not been effectively recycled and treated, and most of them are still treated by storage and landfill, which has caused a great waste of resources and caused serious harm to the human body and the environment. Therefore, studying the resource utilization of solid waste has become an urgent problem to be solved. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a filling material for abandoned pipes; The second object of the present invention is to provide a method for preparing a waste pipe filling material; The third object of the present invention is to provide a method for using waste pipe filling materials.

[0005] The technical solution of the present invention to solve the above technical problems is: A waste pipe filling material comprises a composite waste solidifying agent and silty soft soil, wherein the composite waste solidifying agent is compounded by dry powder and water, wherein the dry powder comprises slag powder, carbide slag and desulfurized gypsum.

[0006] Preferably, the ratio of the dry powder to water is 2:1.

[0007] Preferably, based on the total mass of dry powder of the composite waste solidifying agent, the mass percentage of the slag powder is 50%-80%; the mass percentage of the carbide slag is 5%-37.5%; and the mass percentage of the desulfurized gypsum is 5%-37.5%.

[0008] Preferably, the mass percentage of the slag powder is 80%; the mass percentage of the carbide slag is 5%; and the mass percentage of the desulfurized gypsum is 15%.

[0009] A method for preparing a waste pipe filling material comprises the following steps: S1: Based on the total mass of the curing agent dry powder, take 50-80 parts by weight of slag powder, 5-37.5 parts by weight of carbide slag, 5-37.5 parts by weight of desulfurized gypsum, and 50 parts by weight of water, and stir and mix them at room temperature and dry conditions to obtain a curing agent gel; S2: Based on the original quality of residual muddy soft soil, the curing agent gel is mixed with the soft soil at a dosage of 10%-30%, and the solidified soil filling material is obtained by mixing with a slurry mixer; S3: Pour the solidified soil filling material into the mold, compact it on a cement mortar compaction table for 0.5 to 5 minutes, let it stand for 1 to 3 days, then demould and take it out, and perform curing at a curing temperature of 20±3℃ to obtain the waste pipe filling material.

[0010] A method for applying a waste pipe filling material comprises the following steps: A1: Dig a working well at one end of the abandoned underground pipeline in the city to install the filling equipment; A2: Install the power system, reaction frame and feed hopper in the working pit, where one end of the feed hopper is connected to the power pressure system, and the other end is connected to the waste pipe with a flexible joint according to the diameter of the waste pipe; A3: Pour the mixed solidified soil filling material into the feed hopper, start the power system, and use the power system to press the abandoned pipe filling material into the abandoned pipe until the abandoned pipe is completely filled; A4: After the abandoned pipeline is filled, remove the power system, reaction frame and feed hopper from the working well, and backfill the working well.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The waste pipe filling material of the present invention completely adopts solid waste, namely slag powder, carbide slag and desulfurized gypsum as curing agent, solidifies silty soft soil to prepare waste pipe filling material, has the advantages of wide source of raw materials, simple preparation, high strength and low cost, can fully recycle solid waste, has low energy consumption and low emissions, and can effectively fill urban waste pipes, avoiding ground collapse accidents caused by structural damage of urban waste pipes, which has positive significance for ecological environment and urban development.

[0012] 2. The preparation method of the waste pipe filling material of the present invention has simple process, no carbon dioxide emission, low energy consumption, low preparation cost, and significant economic and social benefits.

[0013] 3. The waste pipe filling material of the present invention can recycle slag powder, carbide slag, and desulfurized gypsum solid waste, solving the problem of their large-scale accumulation. All the raw materials used are solid waste, which improves the utilization rate of solid waste and reduces its impact on the surrounding environment.

[0014] 4. Compared with the currently commonly used pipeline filling materials, the waste pipeline filling material of the present invention does not require high fluidity requirements and does not require the addition of various admixtures, has high compressive strength, and has high comparability.

[0015] 5. In the current pipeline filling method, the single-point grouting length is generally less than 100m. The application method of the abandoned pipeline filling material of the present invention can achieve a longer single-point grouting length by controlling the jacking force, thereby effectively avoiding ground collapse accidents caused by structural damage of abandoned pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the application method of the waste pipe filling material of the present invention.

[0017] DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0019] Example 1 The waste pipe filling material of the present invention comprises a composite waste solidifying agent and muddy soft soil, wherein the composite waste solidifying agent is a compound of slag powder, carbide slag, desulfurized gypsum and water.

[0020] The slag powder used in the following embodiments of the present invention is S95 grade ground granulated blast furnace slag powder, and its chemical composition is shown in Table 1.

[0021] Table 1 Chemical composition of slag powder The carbide slag used is a powder that passes through a standard sieve with an aperture of 300 meshes, and its chemical composition is shown in Table 2.

[0022] Table 2 Chemical composition of carbide slag

[0023] The desulfurized gypsum used is a powder that passes through a standard sieve with an aperture of 300 meshes, and its chemical composition is shown in Table 3.

[0024] Table 3 Main chemical composition of desulfurized gypsum

[0025] The silty soft soil used was taken from a construction site in Dongguan. Its basic physical properties and chemical composition are shown in Tables 4 and 5.

[0026] Table 4 Basic physical properties of silty soft soil

[0027] Table 5 Chemical composition of silty soft soil

[0028] Design the curing agent ratio. Based on the mass of the curing agent dry powder, the mass ratio of slag powder is 50%-80%, the mass ratio of carbide slag is 5%-37.5%, the mass ratio of desulfurized gypsum is 5%-37.5%, and the mass ratio of water is 50%. A total of 12 groups of curing agent ratios are designed, as shown in Table 6. Take the weight of each material according to the curing agent ratio and stir it in a pure slurry mixer for 5 minutes. Stir evenly to obtain a cementitious material.

[0029] Table 6 Curing agent ratio table

[0030] The strength of the cementitious materials prepared in each ratio in this embodiment was tested (GB / T 17671), and it was found that the unconfined compressive strength of the cementitious materials in each ratio in this embodiment was greater than 9.78 MPa at the strength age of 3d, and the maximum strength reached 19.74 MPa; the unconfined compressive strength was greater than 9.39 MPa at 7d, and the maximum strength reached 21.99 MPa; the unconfined compressive strength was greater than 10.79 MPa at 14d, and the maximum strength reached 25.80 MPa; the unconfined compressive strength was greater than 13.57 MPa at 28d, and the maximum strength reached 33.60 MPa.

[0031] The first group of curing agents in Table 6 of Example 1 was used to solidify the muddy soft soil to prepare the abandoned pipeline filling material. Based on the original quality of the residual muddy soft soil, the curing agent gel was mixed with the soft soil at a dosage of 10%-30%, and the solidified soil filling material was obtained by stirring with a slurry mixer. The unconfined compressive strength at 7d and 28d was tested, and the cement curing agent was used for curing and the slag powder + sodium citrate + gypsum were used as curing agents for comparison. The test results are shown in Table 7.

[0032] Table 7: Test results comparison table

[0033] From the test results in Table 7, it can be concluded that by comparing the curing agent of "slag powder + carbide slag + gypsum + sodium citrate" with the curing agent of OPC42.5 for curing silt soil, the curing agent prepared by "slag powder + carbide slag + gypsum" has a better curing result for the original silty soft soil.

[0034] At 10% dosage, the strength of the solidified body of "slag powder + carbide slag + gypsum + sodium citrate" at 28 days is 0.03MPa, and the strength of the solidified body of "slag powder + carbide slag + gypsum" at 28 days is 1.65MPa; When the dosage is 20%, the strength of the solidified body of "slag powder + carbide slag + gypsum + sodium citrate" at 28 days is 0.11MPa, and the strength of the solidified body of "slag powder + carbide slag + gypsum" at 28 days is 5.79MPa; When the dosage is 30%, the strength of the solidified body of "slag powder + carbide slag + gypsum + sodium citrate" at 28 days is 0.25MPa, and the strength of the solidified body of "slag powder + carbide slag + desulfurization gypsum" at 28 days is 8.37MPa.

[0035] By optimizing the original formula of "slag powder + carbide slag + gypsum + sodium citrate", the new curing agent, namely "slag powder + carbide slag + gypsum", not only has a better curing effect, but also greatly improves the strength and further reduces the cost.

[0036] Compared with traditional cement curing agents, the "slag powder + carbide slag + gypsum" curing agent of the present invention has an unconfined compressive strength at 28 days that is greater than that of the cement solidified body. The 28-day strength of different curing agent dosages is 135.71%, 219.89% and 143.31% higher than that of the cement solidified body, respectively. "Slag powder + carbide slag + desulfurized gypsum" has an excellent effect in curing original silty soft soil and is more suitable for the strength requirements of abandoned pipe filling.

[0037] Example 2 The waste pipe filling material prepared in Example 1 is used for waste pipe filling, such as Figure 1 As shown, the following steps are included: (1) Dig a working pit at one end of the urban underground pipeline to install the filling equipment; (2) Install the power system, reaction frame and feed hopper in the working pit, wherein one end of the feed hopper is connected to the power pressure system, and the other end is connected to the waste pipe with a flexible joint according to the diameter of the waste pipe; (3) Pour the pre-mixed solidified soil filling material into the feed hopper, start the power system, and use the power system to press the solidified soil filling material into the abandoned pipe until the abandoned pipe is completely filled; (4) After the abandoned pipeline is filled, remove the power system, reaction frame and feed hopper from the working pit and backfill the working pit.

[0038] The above is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A waste pipe filling material, characterized in that: It includes a composite waste solidifying agent and silty soft soil, wherein the composite waste solidifying agent is composed of dry powder and water, and wherein the dry powder includes slag powder, carbide slag and desulfurized gypsum.

2. The waste pipe filling material according to claim 1, characterized in that: The ratio of the dry powder to water is 2:

1.

3. The waste pipe filling material according to claim 1, characterized in that: In the dry powder, the mass percentage of the slag powder is 50%-80%; the mass percentage of the carbide slag is 5%-37.5%; and the mass percentage of the desulfurized gypsum is 5%-37.5%.

4. The waste pipe filling material according to claim 2, characterized in that: The mass percentage of the slag powder is 80%; the mass percentage of the carbide slag is 5%; and the mass percentage of the desulfurized gypsum is 15%.

5. A method for preparing the waste pipe filling material according to any one of claims 1 to 4, characterized in that: The steps include: S1: Based on the total mass of the curing agent dry powder, take 50-80 parts by weight of slag powder, 5-37.5 parts by weight of carbide slag, 5-37.5 parts by weight of desulfurized gypsum, and 50 parts by weight of water, and stir and mix them at room temperature and dry conditions to obtain a curing agent gel; S2: Based on the original quality of residual muddy soft soil, the curing agent gel is mixed with the soft soil at a dosage of 10%-30%, and the solidified soil filling material is obtained by mixing with a pure slurry mixer; S3: Pour the solidified soil filling material into the mold, compact it on a cement mortar compaction table for 0.5 to 5 minutes, let it stand for 1 to 3 days, then demould and take it out, and perform curing at a curing temperature of 20±3℃ to obtain the waste pipe filling material.

6. A method for applying the waste pipe filling material according to any one of claims 1 to 4, characterized in that: The following steps are involved: A1: Dig a working well at one end of the abandoned underground pipeline in the city to install the filling equipment; A2: Install the power system, reaction frame and feed hopper in the working pit, where one end of the feed hopper is connected to the power pressure system, and the other end is connected to the waste pipe with a flexible joint according to the diameter of the waste pipe; A3: Pour the mixed solidified soil filling material into the feed hopper, start the power system, and use the power system to press the abandoned pipe filling material into the abandoned pipe until the abandoned pipe is completely filled; A4: After the abandoned pipeline is filled, remove the power system, reaction frame and feed hopper from the working well, and backfill the working well.

Images