Preparation method of roadbed filler based on sludge

Abstract

The invention discloses a preparation method of a roadbed filler based on sludge, and belongs to the technical field of road engineering, and the method comprises the following steps: collecting part of sludge in advance, removing large-particle impurities, airing the sludge, and triturating the sludge after airing to prepare dry sludge particles; the method comprises the steps that the maximum particle size of muck in sludge is preset, muck exceeding the preset maximum particle size of muck in the sludge is filtered out through a filtering device, impurities in the sludge are removed, and the water content of the sludge is made to range from 50% to 60%; sludge particles and a stabilizer are added into the pretreated sludge, the sludge particles, the stabilizer and the sludge are fully stirred and turned, and granules are obtained; and adding a plasticizer and a hardening agent into the granules, and fully stirring, turning and throwing the plasticizer, the hardening agent and the granules to obtain the roadbed filler. The roadbed filler is low in cost and good in stability.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering, in particular to a method for preparing a roadbed filler based on silt. Background Art

[0002] Silt is a soft soil with a natural water content greater than the fluidity limit and a porosity greater than 1.5. It is a modern sediment formed under the conditions of slow water flow in bays, lakes or river bays with the participation of microorganisms. It is rich in organic matter, often gray-black, with low mechanical strength and strong compressibility. If there is silt in the foundation, it is easy to cause the building to sink. With the rapid development of urbanization, the output of construction waste has increased year by year, which has become a major problem for urban management, especially in first- and second-tier cities with high population density. In addition, with increasingly stringent environmental protection requirements, traditional extensive disposal methods such as dumping and abandoning construction waste have become impossible. Therefore, a large amount of construction waste urgently needs to be disposed of and recycled. Using slag to prepare roadbed filler is one of the effective ways to achieve large-scale disposal and resource utilization of construction waste.

[0003] In some areas, engineering waste soil is mostly silty clay, which has the characteristics of high water content, high viscosity, high plasticity index, poor engineering properties, etc., and contains debris such as stones, tiles, concrete blocks, and waste plastics. It cannot be used directly as roadbed filler. In addition, the roadbed filler made of silt in the existing technology has poor stability and requires the addition of a large amount of lime, coal powder or mineral powder as a curing agent, which is costly.

[0004] Therefore, it is necessary to provide a method for preparing a silt-based roadbed filler to solve the problem that the roadbed filler made of silt in the prior art has poor stability, requires the addition of a large amount of lime, coal powder or mineral powder as a curing agent, and has high cost. Summary of the invention

[0005] In order to solve the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing a silt-based roadbed filler, which can solve the problems of poor stability of the roadbed filler made of silt in the prior art, the need to add a large amount of lime, coal powder or mineral powder as a curing agent, and high cost.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] A method for preparing a silt-based roadbed filler is provided, comprising the following steps:

[0008] S1, pre-collecting part of the sludge, removing large particles of impurities, drying the sludge, and crushing it after drying to make dry sludge particles;

[0009] S2. Pre-treating the sludge, pre-setting the maximum particle size of the debris in the sludge, filtering out the debris in the sludge that exceeds the preset maximum particle size of the debris through a filtering device, and removing impurities in the sludge, so that the moisture content of the sludge is between 50% and 60%;

[0010] S3, adding the sludge particles and stabilizer to the pretreated sludge, and fully stirring and tossing the sludge particles and stabilizer with the sludge to obtain pellets;

[0011] S4, adding a plasticizer and a hardener to the granular material, and fully stirring and tossing the plasticizer, hardener and granular material to obtain a roadbed filler.

[0012] Furthermore, the stabilizer includes at least one of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose.

[0013] Furthermore, when the stabilizer is a plurality of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose, the mass fractions of the raw materials used in the stabilizer are as follows:

[0014] (1) When two of the stabilizers are used, the mass ratio of any two stabilizers of sodium alginate, sodium phosphated dextran and sodium carboxymethyl cellulose is 1:1;

[0015] (2) When all three stabilizers are used, the mass ratio of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose is 1:1:1.

[0016] Furthermore, the mass ratio of the stabilizer to the sludge particles is (1.5-2):8.

[0017] Furthermore, the hardener includes at least one of methyltrimethoxysilane and methylphenyldimethoxysilane.

[0018] Furthermore, when the hardener is methyltrimethoxysilane and methylphenyldimethoxysilane, the mass ratio of methyltrimethoxysilane to methylphenyldimethoxysilane is 1:1.

[0019] Furthermore, the mass ratio of the plasticizer, the hardener and the granules is 1:1:(7-8).

[0020] Furthermore, the plasticizer includes styrene acrylic rubber and SBS rubber, and the mass ratio of the styrene acrylic rubber to the SBS rubber is 1:1.

[0021] Furthermore, the stirring is achieved by a stirrer, the blade speed of the stirrer is at least 80 r / min, and the stirring temperature of the stirrer is at least 20°C.

[0022] Furthermore, the turning and polishing is achieved by a turning and polishing machine, the blade speed of the turning and polishing machine is 100-400r / min, and the turning and polishing temperature of the turning and polishing machine is at least 30°C.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: sludge, as a common waste, is converted into roadbed filler, which realizes the recycling of resources and reduces the pollution of waste to the environment; in the preparation process, the purity of the filler is ensured by filtering and removing impurities, and its environmental protection performance is further improved; sludge particles are prepared by drying and crushing, which can enhance the strength and stability of the roadbed and improve the utilization rate of the sludge. The sludge particles play a role of filling and reinforcing in the roadbed, making the roadbed more compact and uniform; in the pretreatment process, the water content of the sludge is controlled between 50% and 60%, which is conducive to ensuring the compaction and stability of the roadbed filler; the addition of stabilizers, plasticizers and hardeners in combination with sludge particles can further improve the water resistance, durability and crack resistance of the roadbed filler, making the roadbed more solid and durable, and reducing the cost compared to the use of lime, coal powder or mineral powder. DETAILED DESCRIPTION

[0024] The exemplary embodiments of the present disclosure will be described in more detail below. Although the exemplary embodiments of the present disclosure are shown below, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0025] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0027] Embodiment 1:

[0028] 1. Materials:

[0029] (1) Part of the sludge collected in advance;

[0030] (2) Silt with a moisture content of 50% ± 2%;

[0031] (3) Stabilizer: sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose, with the mass ratio of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose being 1:1:1;

[0032] (4) Plasticizer, including styrene acrylic rubber and SBS rubber, the mass ratio of styrene acrylic rubber to SBS rubber is 1:1;

[0033] (5) A hardener comprising methyltrimethoxysilane and methylphenyldimethoxysilane, wherein the mass ratio of methyltrimethoxysilane to methylphenyldimethoxysilane is 1:1.

[0034] 2. Preparation method of roadbed filler based on silt Preparation of roadbed filler:

[0035] S1, preparing sludge particles, collecting part of the sludge in advance, removing large particles of impurities, drying the sludge, and crushing the sludge after drying to prepare dry sludge particles;

[0036] S2. Pre-treat the sludge, pre-set the maximum particle size of the debris in the sludge, filter out the debris in the sludge that exceeds the preset maximum particle size of the debris through the filtering device, and remove impurities in the sludge, so that the moisture content of the sludge is 50%±2%;

[0037] S3, adding sludge particles and stabilizer to the pretreated sludge, and fully stirring and tossing the sludge particles and stabilizer with the sludge to obtain pellets;

[0038] S4. Add plasticizer and hardener to the granular material, stir and toss the plasticizer, hardener and granular material thoroughly to obtain roadbed filler.

[0039] Embodiment 2:

[0040] 1. Materials:

[0041] (1) Part of the sludge collected in advance;

[0042] (2) Silt with a moisture content of 50% ± 2%;

[0043] (3) Stabilizer: sodium alginate;

[0044] (4) Plasticizer, including styrene acrylic rubber and SBS rubber, the mass ratio of styrene acrylic rubber to SBS rubber is 1:1;

[0045] (5) A hardener comprising methyltrimethoxysilane and methylphenyldimethoxysilane, wherein the mass ratio of methyltrimethoxysilane to methylphenyldimethoxysilane is 1:1.

[0046] 2. Preparation method of roadbed filler based on silt Preparation of roadbed filler:

[0047] S1, preparing sludge particles, collecting part of the sludge in advance, removing large particles of impurities, drying the sludge, and crushing the sludge after drying to prepare dry sludge particles;

[0048] S2. Pre-treat the sludge, pre-set the maximum particle size of the debris in the sludge, filter out the debris in the sludge that exceeds the preset maximum particle size of the debris through the filtering device, and remove impurities in the sludge, so that the moisture content of the sludge is 50%±2%;

[0049] S3, adding sludge particles and stabilizer to the pretreated sludge, and fully stirring and tossing the sludge particles and stabilizer with the sludge to obtain pellets;

[0050] S4. Add plasticizer and hardener to the granular material, stir and toss the plasticizer, hardener and granular material thoroughly to obtain roadbed filler.

[0051] It can be understood that the only difference between Example 2 and Example 1 is the choice of stabilizer. Example 1 uses sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose as stabilizers, and the mass ratio of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose is 1:1:1; Example 2 only uses sodium alginate as a stabilizer.

[0052] Embodiment 3:

[0053] 1. Materials:

[0054] (1) Part of the sludge collected in advance;

[0055] (2) Silt with a moisture content of 50% ± 2%;

[0056] (3) Stabilizer: sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose, with the mass ratio of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose being 1:1:1;

[0057] (4) Plasticizer, including styrene acrylic rubber and SBS rubber, the mass ratio of styrene acrylic rubber to SBS rubber is 1:1;

[0058] (5) Hardener: methyltrimethoxysilane.

[0059] 2. Preparation method of roadbed filler based on silt Preparation of roadbed filler:

[0060] (1) Preparing sludge particles: collecting part of the sludge in advance, removing large particles of impurities, and then drying the sludge. After drying, the sludge is crushed to prepare dry sludge particles;

[0061] (2) Pre-treat the sludge, pre-set the maximum particle size of the debris in the sludge, filter out the debris in the sludge that exceeds the preset maximum particle size through a filtering device, and remove impurities in the sludge, so that the moisture content of the sludge is 50% ± 2%;

[0062] (3) adding sludge particles and a stabilizer to the pretreated sludge, and fully stirring and tossing the sludge particles and the stabilizer with the sludge to obtain pellets;

[0063] (4) Add plasticizer and hardener to the granular material, stir and toss the plasticizer, hardener and granular material thoroughly to obtain the roadbed filler.

[0064] It can be understood that the only difference between Example 3 and Example 1 is the choice of hardener. Example 1 uses methyltrimethoxysilane and methylphenyldimethoxysilane as hardeners, and the mass ratio of methyltrimethoxysilane to methylphenyldimethoxysilane is 1:1; Example 3 uses methyltrimethoxysilane as the hardener.

[0065] Comparative Example 1:

[0066] 1. Materials:

[0067] (1) Lime;

[0068] (2) Silt with a moisture content of 50% ± 2%;

[0069] (3) Stabilizer: sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose, with the mass ratio of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose being 1:1:1;

[0070] (4) Plasticizer, including styrene acrylic rubber and SBS rubber, the mass ratio of styrene acrylic rubber to SBS rubber is 1:1;

[0071] (5) A hardener comprising methyltrimethoxysilane and methylphenyldimethoxysilane, wherein the mass ratio of methyltrimethoxysilane to methylphenyldimethoxysilane is 1:1.

[0072] 2. Preparation method of roadbed filler based on silt Preparation of roadbed filler:

[0073] (1) Pre-treat the sludge, pre-set the maximum particle size of the debris in the sludge, filter out the debris in the sludge that exceeds the preset maximum particle size through the filtering device, and remove impurities in the sludge, so that the moisture content of the sludge is 50%±2%;

[0074] (2) adding lime and stabilizer to the pretreated sludge, and fully stirring and tossing the lime and stabilizer with the sludge to obtain pellets;

[0075] (3) Add plasticizer and hardener to the granular material, stir and toss the plasticizer, hardener and granular material thoroughly to obtain the roadbed filler.

[0076] It can be understood that the only difference between Comparative Example 1 and Example 1 is that Example 1 uses sludge particles; Comparative Example 1 uses lime.

[0077] Comparative Example 2:

[0078] 1. Materials:

[0079] (1) Silt with a moisture content of 50% ± 2%;

[0080] (2) Stabilizer: sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose, with the mass ratio of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose being 1:1:1;

[0081] (3) Plasticizer, including styrene acrylic rubber and SBS rubber, the mass ratio of styrene acrylic rubber to SBS rubber is 1:1;

[0082] (5) A hardener comprising methyltrimethoxysilane and methylphenyldimethoxysilane, wherein the mass ratio of methyltrimethoxysilane to methylphenyldimethoxysilane is 1:1.

[0083] 2. Preparation method of roadbed filler based on silt Preparation of roadbed filler:

[0084] (1) Pre-treat the sludge, pre-set the maximum particle size of the debris in the sludge, filter out the debris in the sludge that exceeds the preset maximum particle size through the filtering device, and remove impurities in the sludge, so that the moisture content of the sludge is 50%±2%;

[0085] (2) adding a stabilizer to the pretreated sludge, fully stirring the stabilizer and the sludge, and tossing the stabilizer and the sludge to obtain pellets;

[0086] (3) Add plasticizer and hardener to the granular material, stir and toss the plasticizer, hardener and granular material thoroughly to obtain the roadbed filler.

[0087] It can be understood that the difference between Comparative Example 2 and Example 1 is that no sludge particles are added to the sludge, while Example 1 adds sludge particles; Comparative Example 2 does not add sludge particles.

[0088] Test example:

[0089] The hardness analysis was performed on the roadbed fillers obtained in Examples 1-3 and Comparative Examples 1-2 to evaluate the stability of the roadbed fillers during use.

[0090] 1. Experimental materials:

[0091] The roadbed fillers prepared in Examples 1-3 were used as samples, the roadbed filler prepared in Comparative Example 1 using lime was used as a sample, and the roadbed filler prepared in Comparative Example 2 without adding silt particles into the silt was used as a sample.

[0092] 2. Experimental process:

[0093] 1. All samples were laid on the ground, and asphalt was laid on the surface of the samples. Three groups of experiments were performed for each embodiment and each comparative example.

[0094] 2. After the asphalt is dried, the asphalt is hammered with the same force and for the same duration until cracks are formed on the asphalt surfaces in Examples 1-3 and Comparative Examples 1-2.

[0095] 3. Experimental results and analysis:

[0096] After hammer testing, we got the following results:

[0097] 1. The asphalt on the roadbed filler prepared in Examples 1-3 maintained good stability in appearance, hardness, etc., and cracks appeared after an average of 60 hammerings in each example.

[0098] 2. Compared with Example 1, the roadbed filler made of lime as a curing agent in Comparative Example 1 also maintained good stability in appearance, hardness, etc., and cracks appeared at the 58th hammering on average in three experiments, which shows that the roadbed filler of the present invention is more stable, reliable and hard than the existing roadbed filler made of lime as a curing agent, and is suitable for long-term use.

[0099] 3. Compared with Example 1 and Comparative Example 1, in Comparative Example 2, neither silt particles nor lime were used, and the asphalt on the roadbed filler had poor stability in terms of appearance and hardness. On average, cracks appeared at the 10th hammering in the three experiments, indicating that the roadbed filler without the addition of silt particles and lime had poor stability.

[0100] Specifically, silt, as a common waste, is converted into roadbed filler, which realizes the recycling of resources and reduces the pollution of waste to the environment; in the preparation process, the purity of the filler is ensured by filtering and removing impurities, further improving its environmental performance; silt particles are prepared by drying and crushing, which can enhance the strength and stability of the roadbed and improve the utilization rate of silt. Silt particles play a role of filling and reinforcing in the roadbed, making the roadbed more compact and uniform; during the pretreatment process, the moisture content of the silt is controlled between 50% and 60%, which is conducive to ensuring the compaction and stability of the roadbed filler; the addition of stabilizers, plasticizers and hardeners in combination with silt particles can further enhance the water resistance, durability and crack resistance of the roadbed filler, making the roadbed more solid and durable, and reducing costs compared to the use of lime, coal powder or mineral powder.

[0101] In order to make the stabilizer effectively combine with the sludge, in the above embodiment, at least one of sodium alginate, sodium dextran phosphate and sodium carboxymethyl cellulose can be selected as the raw material of the stabilizer, ensuring the stability and durability of the roadbed filler. These stabilizers can effectively combine with the sludge, improve the overall performance of the filler, and make it more suitable for road construction.

[0102] Furthermore, when two of the stabilizers are used, the mass ratio of any two stabilizers of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose is 1:1;

[0103] When three stabilizers are used, the mass ratio of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose is 1:1:1.

[0104] In order to reduce production costs and ensure the stability and strength of the filler, in the above embodiment, by setting the mass ratio of the stabilizer to the sludge particles to (1.5-2):8, the proper distribution of the stabilizer in the filler is ensured, which neither wastes too much stabilizer nor ensures the stability and strength of the filler. This ratio control makes the preparation of the filler more economical and efficient.

[0105] In order to improve the hardness and strength of the roadbed filler, in the above embodiment, at least one of methyltrimethoxysilane and methylphenyldimethoxysilane is selected as a hardener, which can significantly improve the hardness and strength of the roadbed filler. These hardeners can chemically react with the components in the sludge to form a stable structure, thereby enhancing the load-bearing capacity and durability of the filler.

[0106] Furthermore, when methyltrimethoxysilane and methylphenyldimethoxysilane are used as hardeners, the mass ratio between them is set to 1:1, which can balance the effects of the two hardeners and make the hardening process of the filler more uniform and stable. This ratio control helps to obtain a roadbed filler with better performance.

[0107] In order to make the roadbed filler have both plasticity and strength during the hardening process, in the above embodiment, by setting the mass ratio of plasticizer, hardener and granular material to 1:1:(7-8), it is ensured that the filler maintains a certain plasticity and obtains sufficient strength during the hardening process. This ratio control makes the filler easy to operate during the construction process, while ensuring the quality and service life of the road.

[0108] In order to improve the flexibility and crack resistance of the roadbed filler, in the above embodiment, styrene-acrylic rubber and SBS rubber are selected as plasticizers, which can improve the flexibility and crack resistance of the roadbed filler. These two plasticizers can improve the microstructure of the filler, making it more compact and uniform, thereby improving the overall performance of the filler.

[0109] Furthermore, by using a mixer with a blade speed of at least 80 r / min and a stirring temperature of at least 20° C., sufficient mixing and reaction between the sludge, stabilizer, plasticizer and hardener can be ensured. This efficient stirring process helps to obtain a roadbed filler with better performance.

[0110] Furthermore, the uniformity and stability of the packing can be further improved by using a turning and polishing machine to perform the turning and polishing operation, by setting the blade speed to 100-400 r / min and the turning and polishing temperature to at least 30° C. This turning and polishing process helps to eliminate bubbles and voids in the packing and improve the density and strength of the packing.

[0111] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

[0112] Except for the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features are provided.

Claims

1. A method for preparing a roadbed filler based on silt, characterized in that: The following steps are involved: S1, pre-collecting part of the sludge, removing large particles of impurities, drying the sludge, and crushing the sludge after drying to make dry sludge particles; S2. Pre-treating the sludge, pre-setting the maximum particle size of the debris in the sludge, filtering out the debris in the sludge that exceeds the preset maximum particle size of the debris through a filtering device, and removing impurities in the sludge, so that the moisture content of the sludge is between 50% and 60%; S3, adding the sludge particles and stabilizer to the pretreated sludge, and fully stirring and tossing the sludge particles and stabilizer with the sludge to obtain pellets; S4, adding a plasticizer and a hardener to the granular material, and fully stirring and tossing the plasticizer, hardener and granular material to obtain a roadbed filler.

2. The method for preparing the silt-based roadbed filler according to claim 1, characterized in that: The stabilizer includes at least one of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose.

3. The method for preparing the silt-based roadbed filler according to claim 2, characterized in that: When the stabilizer is a plurality of sodium alginate, sodium dextran phosphate and sodium carboxymethyl cellulose, the mass fractions of the raw materials used in the stabilizer are as follows: (1) When two of the stabilizers are used, the mass ratio of any two stabilizers of sodium alginate, sodium phosphated dextran and sodium carboxymethyl cellulose is 1:1; (2) When all three stabilizers are used, the mass ratio of sodium alginate, sodium phosphorylated dextran and sodium carboxymethyl cellulose is 1:1:

1.

4. The method for preparing the silt-based roadbed filler according to claim 3, characterized in that: The mass ratio of the stabilizer to the sludge particles is (1.5-2):

8.

5. The method for preparing the silt-based roadbed filler according to claim 1, characterized in that: The hardener includes at least one of methyltrimethoxysilane and methylphenyldimethoxysilane.

6. The method for preparing the silt-based roadbed filler according to claim 5, characterized in that: When the hardener is methyltrimethoxysilane and methylphenyldimethoxysilane, the mass ratio of methyltrimethoxysilane to methylphenyldimethoxysilane is 1:

1.

7. The method for preparing the silt-based roadbed filler according to claim 1, characterized in that: The mass ratio of the plasticizer, the hardener and the granules is 1:1:(7-8).

8. The method for preparing the silt-based roadbed filler according to claim 1, characterized in that: The plasticizer comprises styrene acrylic rubber and SBS rubber, and the mass ratio of the styrene acrylic rubber to the SBS rubber is 1:

1.

9. The method for preparing the silt-based roadbed filler according to claim 1, characterized in that: The stirring is achieved by a stirrer, the blade speed of the stirrer is at least 80 r / min, and the stirring temperature of the stirrer is at least 20°C.

10. The method for preparing a silt-based roadbed filler according to claim 1, characterized in that: The turning and polishing is achieved by using a turning and polishing machine, the blade speed of the turning and polishing machine is 100-400r / min, and the turning and polishing temperature of the turning and polishing machine is at least 30°C.