Cement mixing pile and construction method thereof

Abstract

The application relates to the technical field of concrete pipe piles, and particularly discloses a cement mixing pile and a construction method thereof. A cement mixing pile, raw materials of the mixing pile include the following components in parts by weight: cement 200-400 parts, yellow sand 450-1000 parts, stone 750-1000 parts, water 80-260 parts, mineral material 30-80 parts, fiber 20-150 parts, activator 10-20 parts, anti-permeation agent 10-20 parts, water reducing agent 7-35 parts, silicon micro powder 10-15 parts, sodium carbonate 10-15 parts, phenolic resin 10-15 parts, and chitosan modified temperature-resistant filler 30-50 parts. A construction method of the cement mixing pile comprises the following steps: uniformly mixing raw materials such as cement to obtain slurry; and forcibly stirring the slurry by using a deep-layer stirring machine to obtain the cement mixing pile.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete pipe piles, in particular to a cement mixing pile and a construction method thereof. BACKGROUND

[0002] The cement mixing pile is formed by a special deep mixer that forcibly mixes soft soil and cement, and a series of physical and chemical reactions between the cement and the soft soil are utilized to consolidate the soil body and form a cement-soil pile with integrity, water stability and certain strength. The cement mixing pile is mainly used for soft soil foundation treatment.

[0003] The concrete used in the cement mixing pile needs to have high strength to meet the effect of stable support of the foundation. In addition, since the cement mixing pile is generally used for a long time, it also needs to have good durability to maintain good support effect in the long-term use. However, most commonly used cement mixing piles are difficult to maintain good strength for a long time in harsh environments such as high salt, high humidity and large temperature difference, causing safety hazards. SUMMARY

[0004] In order to improve the durability of the formed cement mixing pile, the present application provides a cement mixing pile and a construction method thereof.

[0005] In a first aspect, the present application provides a cement mixing pile, which adopts the following technical solution:

[0006] A cement mixing pile, the raw materials of the mixing pile include the following components in parts by weight: cement 200-400 parts, yellow sand 450-1000 parts, stone 750-1000 parts, water 80-260 parts, mineral material 30-80 parts, fiber 20-150 parts, activator 10-20 parts, anti-permeation agent 10-20 parts, water reducing agent 7-35 parts, silicon powder 10-15 parts, sodium carbonate 10-15 parts, phenolic resin 10-15 parts, chitosan modified temperature-resistant filler 30-50 parts.

[0007] By using the above technical solution, the combination of silicon powder, sodium carbonate and phenolic resin can improve the strength of the formed cement mixing pile. The chitosan on the surface of the chitosan modified temperature-resistant filler can be fully dispersed, so that the formed cement mixing pile has good high and low temperature resistance. In addition, chitosan also has good moisture absorption performance, thereby improving the anti-permeation performance of the cement mixing pile. Phenolic resin also has high anti-aging performance, thereby improving the durability of the formed cement mixing pile.

[0008] In one specific embodiment, the method for preparing the chitosan modified temperature-resistant filler comprises the following steps: dispersing temperature-resistant powder in water to obtain a temperature-resistant powder dispersion; adding chitosan to an aqueous acetic acid solution, stirring until the chitosan is completely dissolved, to obtain a chitosan solution; adding the temperature-resistant powder dispersion to the chitosan solution, stirring until the mixture is uniform, to obtain a mixture;

[0009] adding glutaraldehyde to the mixture, stirring until the mixture is uniform, standing, adding a sodium hydroxide solution, soaking, filtering, washing, drying, and grinding, to obtain the chitosan modified temperature-resistant filler.

[0010] By using the above technical solution, the temperature-resistant powder is first dispersed in water to obtain a temperature-resistant powder dispersion, then the chitosan is dissolved, the two are mixed to obtain a mixture, and finally glutaraldehyde is added to coat the temperature-resistant powder with chitosan, thereby obtaining a chitosan modified temperature-resistant filler with good dispersion performance.

[0011] In one specific embodiment, the temperature-resistant powder comprises a mixture of fumed silica and carbon nanotubes.

[0012] By using the above technical solution, the fumed silica has good low-temperature resistance, and the carbon nanotubes can make the chitosan modified temperature-resistant filler have good high-temperature resistance, thereby making the cement mixing pile obtained have high temperature resistance.

[0013] In one specific embodiment, the weight ratio of the temperature-resistant powder dispersion to the chitosan solution is 1:(8-10).

[0014] By using the above technical solution, the ratio of temperature-resistant powder to chitosan is further limited, so that the modification effect of chitosan on temperature-resistant powder is good, thereby improving the dispersion performance of the chitosan modified temperature-resistant filler prepared.

[0015] In one specific embodiment, the mineral material comprises one or more of silica powder, metakaolin, fly ash, and lime.

[0016] By using the above technical solution, the addition of silica powder, metakaolin, fly ash, and lime can improve the durability of the cement mixing pile in a salt corrosion environment.

[0017] In one specific embodiment, the fiber comprises a mixture of one or both of polypropylene fiber and natural fiber.

[0018] By using the above technical solution, the addition of polypropylene fiber and natural fiber can improve the shrinkage performance of the cement mixing pile.

[0019] In one specific implementation, the activator includes one or more of gypsum, baking soda, sodium hydrogen phosphate.

[0020] By adopting the above technical solution, gypsum, baking soda and sodium hydrogen phosphate have good activation effect, so that the mechanical properties of the cement mixing pile in the early stage can be improved.

[0021] In one specific implementation, the anti-permeation agent includes one or more of polyacrylamide, starch and pectin.

[0022] By adopting the above technical solution, the addition of polyacrylamide, starch and pectin can improve the anti-permeation performance of the cement mixing pile.

[0023] In one specific implementation, the water-reducing agent is a polycarboxylic acid water-reducing agent.

[0024] In a second aspect, the application provides a construction method of a cement mixing pile, which adopts the following technical solution:

[0025] A construction method of a cement mixing pile, comprising the following steps:

[0026] Cement, yellow sand, stones, water, mineral materials, fibers, activators, anti-permeation agents, water-reducing agents, silica powder, sodium carbonate, phenolic resin and chitosan modified temperature-resistant filler are mixed uniformly to obtain a slurry;

[0027] The slurry is forcibly stirred by using a deep mixer to obtain a cement mixing pile.

[0028] By adopting the above technical solution, the raw materials of cement, yellow sand, stones, water, mineral materials, fibers, activators, anti-permeation agents, water-reducing agents, silica powder, sodium carbonate, phenolic resin and chitosan modified temperature-resistant filler are first mixed uniformly to obtain a slurry, and then the slurry is forcibly stirred by using a deep mixer to obtain a cement mixing pile with good durability.

[0029] In summary, the application has the following at least one beneficial technical effect:

[0030] 1. In the application, the cooperation of silica powder, sodium carbonate and phenolic resin can improve the strength of the formed cement mixing pile, the chitosan on the surface of the chitosan modified temperature-resistant filler can be fully dispersed, the formed cement mixing pile has good high and low temperature resistance, in addition, chitosan also has good moisture absorption performance, thereby improving the anti-permeation performance of the cement mixing pile, and the phenolic resin also has high anti-aging performance, thus improving the durability of the formed cement mixing pile;

[0031] 2. The temperature-resistant powder in the application is a mixture of fumed silica and carbon nanotubes. Fumed silica has good low-temperature resistance, and carbon nanotubes can make the chitosan modified temperature-resistant filler have good high-temperature resistance, so that the obtained cement mixing pile has high temperature resistance;

[0032] 3. The construction method in the application, first, the raw materials cement, yellow sand, stone, water, mineral material, fiber, activator, anti-permeation agent, water reducing agent, silica powder, sodium carbonate, phenolic resin, chitosan modified temperature-resistant filler are mixed and stirred uniformly to prepare a slurry, then the slurry is forcedly stirred by using a deep mixer to obtain a cement mixing pile with good durability. DETAILED DESCRIPTION

[0033] The application will be further described in detail below in combination with examples.

[0034] All raw materials in the examples can be obtained by market purchase. Among them, the polycarboxylic acid water reducing agent has CAS number: 27599-56-0.

[0035] Preparation Example

[0036] Preparation Example 1

[0037] Preparation Example 1 provides a preparation method of chitosan modified temperature-resistant filler, which comprises the following steps:

[0038] The temperature-resistant powder is ultrasonically dispersed in water to obtain a temperature-resistant powder dispersion liquid; chitosan is added to a 1% acetic acid aqueous solution and stirred uniformly to make the chitosan completely dissolved, thereby obtaining a chitosan solution; the temperature-resistant powder dispersion liquid is added to the chitosan solution and stirred uniformly to obtain a mixed liquid; wherein the temperature-resistant powder is a mixture of fumed silica and carbon nanotubes, and the weight ratio of fumed silica to carbon nanotubes is 1:1; the mass fraction of the temperature-resistant powder in the temperature-resistant powder dispersion liquid is 4%; the mass fraction of chitosan in the chitosan solution is 0.3%; the weight ratio of the temperature-resistant powder dispersion liquid to the chitosan solution is 1:7; glutaraldehyde is added to the mixed liquid, stirred for 55 min, and then left to stand for 10 h; an appropriate amount of 0.1 mol / L sodium hydroxide solution is added and soaked to make the mixed liquid into a gel; the gel is filtered, washed, dried, and ground to obtain the chitosan modified temperature-resistant filler; wherein the weight ratio of glutaraldehyde to chitosan is 8:5.

[0039] Preparation Example 2

[0040] Preparation Example 2 and Preparation Example 1 differ in that the weight ratio of the temperature-resistant powder dispersion liquid to the chitosan solution is 1:8; the remaining steps are consistent with those of Preparation Example 1.

[0041] Preparation Example 3

[0042] Preparation Example 3 is different from Preparation Example 1 in that the weight ratio of the temperature-resistant powder dispersion liquid to the chitosan solution is 1:9; the remaining steps are consistent with those of Preparation Example 1.

[0043] Preparation Example 4

[0044] Preparation Example 4 is different from Preparation Example 1 in that the weight ratio of the temperature-resistant powder dispersion liquid to the chitosan solution is 1:10; the remaining steps are consistent with those of Preparation Example 1.

[0045] Preparation Example 5

[0046] Preparation Example 5 is different from Preparation Example 1 in that the weight ratio of the temperature-resistant powder dispersion liquid to the chitosan solution is 1:11; the remaining steps are consistent with those of Preparation Example 1.

[0047] Preparation Example 6

[0048] Preparation Example 6 is different from Preparation Example 3 in that the temperature-resistant powder is fumed silica; the remaining steps are consistent with those of Preparation Example 3.

[0049] Preparation Example 7

[0050] Preparation Example 7 is different from Preparation Example 3 in that the temperature-resistant powder is carbon nanotube; the remaining steps are consistent with those of Preparation Example 3.

[0051] Example

[0052] Example 1

[0053] Example 1 provides a construction method of a cement mixing pile, comprising the following steps:

[0054] 200 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, 10 kg of silica powder, 10 kg of sodium carbonate, 10 kg of phenolic resin, 30 kg of chitosan modified temperature-resistant filler in Preparation Example 1 are uniformly mixed to obtain a slurry; wherein the mineral material is a mixture composed of silica powder, fly ash and lime, and the weight ratio of the silica powder, the fly ash and the lime is 1:1:1; the fiber is a mixture composed of polypropylene fiber and natural fiber, and the weight ratio of the polypropylene fiber and the natural fiber is 1:1; the activator is baking soda; the impermeability agent is polyacrylamide; the water reducing agent is polycarboxylic acid water reducing agent;

[0055] The slurry is added to the hopper in the deep agitator, and then the deep agitator is pre-agitated and sunk; the deep agitator turntable is started to agitate and sink, after sinking to the pre-designed depth, the mortar pump is started, the slurry is sent to the mortar outlet of the agitator head through the pipeline, after the slurry is discharged, the agitator and the tensioning chain device are started, the drilling rod is lifted at the designed lifting speed, the slurry and the soil are fully mixed; after the agitator head is lifted to 500 mm above the top of the pile, the mortar pump is turned off, the agitator is repeatedly sunk to the designed depth, and finally the mortar is repeatedly mixed and lifted until the ground, and the construction of the cement mixing pile is completed.

[0056] Example 2

[0057] Example 2 differs from Example 1 in that 200 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, 10 kg of silica powder, 10 kg of sodium carbonate, 10 kg of phenolic resin, and 30 kg of the chitosan modified temperature resistant filler in Preparation Example 2 are uniformly mixed to obtain a slurry; the remaining steps are consistent with Example 1.

[0058] Example 3

[0059] Example 3 differs from Example 1 in that 200 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, 10 kg of silica powder, 10 kg of sodium carbonate, 10 kg of phenolic resin, and 30 kg of the chitosan modified temperature resistant filler in Preparation Example 3 are uniformly mixed to obtain a slurry; the remaining steps are consistent with Example 1.

[0060] Example 4

[0061] Example 4 differs from Example 1 in that 200 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, 10 kg of silica powder, 10 kg of sodium carbonate, 10 kg of phenolic resin, and 30 kg of the chitosan modified temperature resistant filler in Preparation Example 4 are uniformly mixed to obtain a slurry; the remaining steps are consistent with Example 1.

[0062] Example 5

[0063] Example 5 differs from Example 1 in that 200 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, 10 kg of silica powder, 10 kg of sodium carbonate, 10 kg of phenolic resin, 30 kg of chitosan modified temperature resistant filler in Preparation Example 2 are uniformly stirred and mixed to obtain a slurry; the remaining steps are consistent with Example 5.

[0064] Example 6

[0065] Example 6 differs from Example 1 in that 200 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, 10 kg of silica powder, 10 kg of sodium carbonate, 10 kg of phenolic resin, 30 kg of chitosan modified temperature resistant filler in Preparation Example 2 are uniformly stirred and mixed to obtain a slurry; the remaining steps are consistent with Example 6.

[0066] Example 7

[0067] Example 7 differs from Example 1 in that 200 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, 10 kg of silica powder, 10 kg of sodium carbonate, 10 kg of phenolic resin, 30 kg of chitosan modified temperature resistant filler in Preparation Example 2 are uniformly stirred and mixed to obtain a slurry; the remaining steps are consistent with Example 7.

[0068] Example 8

[0069] Example 8 differs from Example 3 in that 300 kg of cement, 700 kg of yellow sand, 850 kg of stone, 160 kg of water, 55 kg of mineral material, 85 kg of fiber, 15 kg of activator, 15 kg of impermeability agent, 22 kg of water reducing agent, 12.5 kg of silica powder, 12.5 kg of sodium carbonate, 12.5 kg of phenolic resin, 40 kg of chitosan modified temperature resistant filler in Preparation Example 3 are uniformly stirred and mixed to obtain a slurry; the remaining steps are consistent with Example 3.

[0070] Example 9

[0071] Example 9 differs from Example 3 in that 400 kg of cement, 1000 kg of yellow sand, 1000 kg of stone, 260 kg of water, 80 kg of mineral material, 150 kg of fiber, 20 kg of activator, 20 kg of impermeability agent, 35 kg of water reducing agent, 15 kg of silica powder, 15 kg of sodium carbonate, 15 kg of phenolic resin, and 50 kg of the chitosan-modified temperature-resistant filler in Preparation Example 3 are uniformly stirred and mixed to obtain a slurry; the remaining steps are consistent with Example 3.

[0072] Comparative Example

[0073] Comparative Example 1

[0074] Comparative Example 1 differs from Example 1 in that 230 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, and 30 kg of the chitosan-modified temperature-resistant filler in Preparation Example 2 are uniformly stirred and mixed to obtain a slurry; the remaining steps are consistent with Example 1.

[0075] Comparative Example 2

[0076] Comparative Example 2 differs from Example 1 in that 200 kg of cement, 450 kg of yellow sand, 750 kg of stone, 80 kg of water, 30 kg of mineral material, 20 kg of fiber, 10 kg of activator, 10 kg of impermeability agent, 7 kg of water reducing agent, 10 kg of silica powder, 10 kg of sodium carbonate, 10 kg of phenolic resin, and 30 kg of temperature-resistant filler are uniformly stirred and mixed to obtain a slurry; the temperature-resistant filler is a mixture of fumed silica and carbon nanotubes, and the weight ratio of fumed silica to carbon nanotubes is 1:1; the remaining steps are consistent with Example 1.

[0077] Performance detection test durability: according to GB / T50082-2009 "Standard for Testing Methods for Long-term Performance and Durability of Ordinary Concrete", the carbonation depth of the cement mixing pile at 28 days is detected, and the smaller the carbonation depth, the better the durability.

[0078] Temperature resistance: through a detection agency, the high and low temperature resistance number of the cement mixing pile is detected.

[0079] Table 1 Performance detection results of the cement mixing pile

[0080]

[0081] In combination with Embodiment 1 and Comparative Examples 1-2, the cement mixing pile in Embodiment 1 has better durability and excellent temperature resistance, which shows that when the slurry is prepared, the silica fume, sodium carbonate and phenolic resin are added to the raw materials, and the strength of the cement mixing pile is improved by using the combination of the three, thereby improving the durability of the cement mixing pile; the chitosan modified temperature-resistant filler is added to the raw materials, and the hydrophilic property of chitosan is used to make the chitosan modified temperature-resistant filler uniformly dispersed in the slurry, thereby improving the temperature resistance of the cement mixing pile.

[0082] In combination with Embodiments 1-5, the cement mixing pile in Embodiments 2-4 has better temperature resistance, which shows that when the chitosan modified temperature-resistant filler is prepared, the ratio of the temperature-resistant powder dispersion liquid to the chitosan solution is preferably 1:(8-10), and the dispersion performance of the chitosan modified temperature-resistant filler is better, thereby improving the temperature resistance of the cement mixing pile.

[0083] In combination with Embodiment 3, Embodiment 6 and Embodiment 7, the cement mixing pile in Embodiment 3 has the best temperature resistance, which shows that when the chitosan modified temperature-resistant filler is prepared, the temperature-resistant powder is preferably a mixture of fumed silica and carbon nanotubes, and the fumed silica has good low-temperature resistance and the carbon nanotubes have good high-temperature resistance, thereby improving the temperature resistance of the cement mixing pile.

[0084] In combination with Embodiment 3, Embodiment 8 and Embodiment 9, the cement mixing pile in Embodiment 8 has better durability and excellent temperature resistance, which shows that when the slurry is prepared, the use amount of the raw materials is increased, and the performance of the finally formed cement mixing pile shows a trend of first increasing and then decreasing.

[0085] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A cement mixing pile, characterized in that: The raw materials for the mixing pile include the following components by weight: 200-400 parts cement, 450-1000 parts yellow sand, 750-1000 parts gravel, 80-260 parts water, 30-80 parts mineral materials, 20-150 parts fiber, 10-20 parts activator, 10-20 parts anti-permeability agent, 7-35 parts water-reducing agent, 10-15 parts silica powder, 10-15 parts sodium carbonate, 10-15 parts phenolic resin, and 30-50 parts chitosan-modified heat-resistant filler. The preparation method of the chitosan-modified heat-resistant filler includes the following steps: dispersing the heat-resistant powder in water to obtain a heat-resistant powder dispersion. Chitosan is added to an aqueous acetic acid solution and stirred until completely dissolved to obtain a chitosan solution. A heat-resistant powder dispersion is added to the chitosan solution and stirred until homogeneous to obtain a mixed solution. Glutaraldehyde is added to the mixed solution and stirred until homogeneous. The mixture is allowed to stand, then sodium hydroxide solution is added for soaking, followed by filtration, washing, drying, and grinding to obtain a chitosan-modified heat-resistant filler. The heat-resistant powder comprises a mixture of fumed silica and carbon nanotubes. The mineral material comprises one or more of silica powder, metakaolin, fly ash, and lime. The activator comprises one or more of gypsum, baking soda, and sodium hydrogen phosphate.

2. A cement mixing pile according to claim 1, characterized in that: The weight ratio of the heat-resistant powder dispersion to the chitosan solution is 1:(8-10).

3. A cement mixing pile according to claim 1, characterized in that: The fiber includes one or a mixture of two of the following: polypropylene fiber and natural fiber.

4. A cement mixing pile according to claim 1, characterized in that: The impermeability agent includes one or more of polyacrylamide, starch, and pectin.

5. A cement mixing pile according to claim 1, characterized in that: The water-reducing agent is a polycarboxylate water-reducing agent.

6. A construction method for cement mixing piles as described in any one of claims 1-5, characterized in that: The process includes the following steps: mixing cement, yellow sand, gravel, water, mineral materials, fiber, activator, anti-permeability agent, water-reducing agent, silica powder, sodium carbonate, phenolic resin, and chitosan-modified heat-resistant filler evenly to obtain a slurry; Cement mixing piles are obtained by forcibly mixing the slurry using a deep mixer.

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