CN111978040B

CN111978040B - Combined pile for foundation engineering and preparation method thereof

Info

Publication number: CN111978040B
Application number: CN202010840598.0A
Authority: CN
Inventors: 麦小君
Original assignee: Guangdong Jintuo Construction Engineering Co ltd
Current assignee: Guangdong Jintuo Construction Engineering Co ltd
Priority date: 2020-08-20
Filing date: 2020-08-20
Publication date: 2021-12-14
Anticipated expiration: 2040-08-20
Also published as: CN111978040A

Abstract

The invention relates to the field of foundation construction, in particular to a combined pile for foundation engineering and a preparation method thereof. The composite pile comprises cement, a filler, fly ash, a water reducing agent, an anti-permeability agent and a reinforcing agent, wherein the anti-permeability agent is composed of modified silicon dioxide and acrylic resin. When the composite pile is prepared, the materials are uniformly mixed, water is added, the mixture is uniformly stirred and then is injected into a mold, the mold is removed after the mixture is formed, and the composite pile is obtained after the mixture is maintained for 20-30 days. The combined pile for foundation engineering recorded by the invention has the advantages of good impermeability and good mechanical property.

Description

Combined pile for foundation engineering and preparation method thereof

Technical Field

The application relates to the field of foundation construction, in particular to a combined pile for foundation engineering and a preparation method thereof.

Background

At present, when foundation construction is carried out, the foundation needs to be piled, and generally, a combined pile can be driven into the foundation so as to stabilize the foundation.

The common composite pile is made of concrete, and during production, the concrete and water are mixed uniformly to form a gelatinous substance, and then the composite pile can be obtained through molding.

However, when the foundation construction facilities are constructed in a soft soil stratum or a sand drift stratum with large water content, underground water permeates into the pile body through the side wall and the pile bottom of the composite pile, so that the strength of the composite pile is affected.

In view of the above-mentioned related art, the inventors consider that there is a defect that the conventional composite pile for foundation engineering has poor impermeability.

Disclosure of Invention

In view of the defects in the prior art, the first object of the present invention is to provide a composite pile for foundation engineering, which has the advantage of good impermeability.

A second object of the present invention is to provide a method for manufacturing a composite pile for foundation engineering, which is used for manufacturing the composite pile for foundation engineering.

In order to achieve the first object, the invention provides the following technical scheme: a combined pile for foundation engineering is prepared from the following raw materials in parts by weight:

cement of 250 portions and 300 portions;

850 portions of filler and 950 portions;

40-60 parts of fly ash;

3-6 parts of a water reducing agent;

8-16 parts of an anti-permeability agent;

6-10 parts of a reinforcing agent;

170 portions of water and 190 portions of water;

the anti-permeability agent is composed of modified silicon dioxide and acrylic resin, and the modified silicon dioxide is prepared by the following method:

the method comprises the following steps: grinding silicon dioxide to obtain powder with the mesh number of 5000-;

step two: mixing xanthan gum and polyvinyl alcohol in a ratio of 1: (10-20), adding the silicon dioxide powder obtained in the step one, wherein the weight of xanthan gum is 5-10% of that of the silicon dioxide powder, adding water into the mixture, immersing the mixture in the water, performing microwave treatment for 10-20min, adding sodium dodecyl sulfate and sodium methylene naphthalene sulfonate into the solution, the weight of the sodium dodecyl sulfate is 1-2% of that of the silicon dioxide powder, performing ultrasonic treatment for 30-45min, separating and drying to obtain the modified silicon dioxide.

By adopting the technical scheme, cement is used as a cementing material, water is added for stirring to form slurry, the slurry is hardened to form the combined column, and the added filler and the fly ash can effectively improve the mechanical property of the combined column and improve the compactness of the combined column. The water reducing agent is added to reduce the added water and reduce the water-cement ratio. The reinforcing agent can be combined with the filler and the fly ash, so that the compressive strength and the flexural strength of the combined column are improved. The anti-permeability agent is composed of modified silicon dioxide and acrylic resin, wherein the surface of the modified silicon dioxide is anoxic by burning common silicon dioxide twice, the surface of the silicon dioxide can be stabilized by directly placing the modified silicon dioxide in water during the last burning, the xanthan gum and polyvinyl alcohol are mixed and then added into the water to form a gel substance, and the gel substance is tightly adhered to the surface of the silicon dioxide by microwave treatment. And then sodium dodecyl sulfate and sodium methylene naphthalene sulfonate are added, so that the silicon dioxide with polyvinyl alcohol and xanthan gum attached to the surface can be well dispersed in the cement, and the impermeability of the cement can be effectively improved after the cement is hardened and formed. The addition of the acrylic resin can improve the strength of the cement, in addition, the acrylic resin can be well connected with the modified silicon dioxide and well dispersed in the cement, and after the cement is formed, the acrylic resin can well separate external water in the acrylic water, so that the impermeability can be well improved.

Further, the cement is ordinary portland cement.

By adopting the technical scheme, when the ordinary Portland cement is used, the frost resistance and wear resistance of the combined pile can be improved, and in addition, the cost is lower.

Further, the weight ratio of the modified silica to the acrylic resin ranges from (1-3): 1.

by adopting the technical scheme, when the weight ratio range of the modified silicon dioxide to the acrylic resin is (1-3): 1, the acrylic resin and the modified silicon dioxide are well dispersed in the cement, and the mechanical property of the combined column is ensured while the strength of the impermeability of the combined column is ensured.

Further, the weight ratio of the modified silica to the acrylic resin is 2: 1.

by adopting the technical scheme, the weight ratio of the modified silicon dioxide to the acrylic resin is 2:1, the prepared composite pile has better anti-permeability capability and mechanical property.

Further, the acrylic resin is modified acrylic resin and is prepared by the following method:

mixing acrylic resin and perchloroethylene resin according to the weight ratio of 1 (2-3), placing the mixture in water, adding alkylphenol polyoxyethylene ether with the weight of 2-5% of that of the acrylic resin, performing ultrasonic treatment for 10-25min, then adding water with the weight of 3-5 times that of the acrylic resin, uniformly stirring, standing for 1-2h, then adding mannan with the weight of 1-3% of that of the acrylic resin, stirring for 10-15min, heating to 55-60 ℃, keeping for 1-3h, cooling to room temperature, separating and drying to obtain the modified acrylic resin.

By adopting the technical scheme, when the acrylic resin is modified, the alkylphenol ethoxylates is used for modifying the surface of the acrylic resin, so that the dispersibility of the acrylic resin is better, in addition, after the mannan is added, the combination of the acrylic resin and the cement can be improved, so that the impermeability strength of the composite pile is improved, and in addition, the addition of the mannan can improve the antibacterial performance of the composite pile.

mixing acrylic resin and perchloroethylene resin in a weight ratio of 1:2.5, placing the mixture in water, adding alkylphenol polyoxyethylene ether with the weight of 3.5% of that of the acrylic resin, performing ultrasonic treatment for 20min, adding water with the weight of 4 times that of the acrylic resin, uniformly stirring, standing for 1.5h, adding mannan with the weight of 2% of that of the acrylic resin, stirring for 12min, heating to 58 ℃, keeping for 2h, cooling to room temperature, separating and drying to obtain the modified acrylic resin.

By adopting the technical scheme, when the modified acrylic resin is prepared by adopting the method, the prepared modified acrylic resin has better impermeability.

Further, the weight ratio range of the water reducing agent to the anti-permeability agent is 1: (2-4).

By adopting the technical scheme, when the weight ratio range of the water reducing agent to the anti-permeability agent is 1: (2-4), when water is added, less water can be added to reduce the water-cement ratio.

Further, the weight ratio of the water reducing agent to the anti-permeability agent is 1: 3.

by adopting the technical scheme, when the weight ratio of the water reducing agent to the anti-permeability agent is 1: and 3, less water is used, and the prepared composite pile has better properties.

Further, the reinforcing agent is polypropylene fiber, and the length of the polypropylene fiber is 1-10 mm.

By adopting the technical scheme, the strength of the combined pile can be improved by adopting the polypropylene fiber, the connecting force of each substance is improved, and the strength of the combined pile is effectively improved by cooperating with the filler.

Further, the water reducing agent is a polycarboxylic acid water reducing agent.

Through adopting above-mentioned technical scheme, polycarboxylate water reducing agent compares in other water reducing agents, and its quantity is less, in addition, green, the nonflammable can the safe handling.

Furthermore, the filler is sand, and the particle size of the sand is 0.08-2 mm.

By adopting the technical scheme, the sandstone can effectively improve the strength of the composite pile, and when the particle size of the sandstone is 0.08-2mm, the sandstone is easy to disperse in cement and is easy to mix with polypropylene fibers.

Further, the weight ratio of sand with the particle size of 0.08mm, 0.5mm and 2mm is 1:3: 2.

Through adopting above-mentioned technical scheme, the grit uses the graded sand can improve the intensity of composite pile, and uses the graded sand of this proportion, can make each material mix comparatively evenly in the composite pile.

In order to achieve the second object, the invention provides the following technical scheme:

a preparation method of a combined pile for foundation engineering comprises the following steps:

the method comprises the following steps: mixing cement, filler, fly ash, a water reducing agent, an anti-permeability agent and a reinforcing agent, and uniformly stirring;

step two: adding water into the mixed powder, stirring for 3-5min, and stirring well;

step three: injecting the mixture obtained in the step two into a mold, and demolding after the mixture is dried and formed;

step four: and maintaining for 20-30d to obtain the combined pile for foundation engineering.

By adopting the technical scheme, the substances are firstly mixed to be uniformly mixed, then the mixture is added into water and uniformly stirred to form a gel substance, so that the gel substance is convenient to form. Then the mixture is added into a mould, so that the mixture can be well formed, and then maintained, so that the mixture is stable and convenient to use.

Further, the preparation method of the combined pile for foundation engineering comprises the following steps:

step two: adding water into the mixed powder, stirring for 4min, and stirring uniformly;

step four: and maintaining for 28d to obtain the combined pile for the foundation engineering.

By adopting the technical scheme, the composite pile is prepared by adopting the parameters, and the prepared composite pile has better mechanical property and impermeability strength.

In conclusion, the invention has the following beneficial effects:

firstly, because the invention adopts the combination of the modified silicon dioxide and the acrylic resin to form the anti-permeability agent, the surface of the modified silicon dioxide is adhered with the xanthan gum and the polyvinyl alcohol, and the modified silicon dioxide is conveniently dispersed in the cement under the modification of the sodium dodecyl sulfate and the sodium methylene naphthalene sulfonate, and the acrylic resin can be connected with the modified silicon dioxide, thereby effectively improving the anti-permeability capability of the cement.

Secondly, the modified acrylic resin is preferably adopted in the invention, the dispersibility is better, and after the mannan is added, the combination of the acrylic resin and the cement can be improved, so that the impermeability strength of the composite pile is improved, and the addition of the mannan can improve the antibacterial performance of the composite pile.

Thirdly, according to the method, the substances are mixed and added with water to form a gel substance, and then the gel substance is injected into a mold for molding, so that the preparation method is simple, and the prepared composite pile has good properties.

Detailed Description

The present invention will be described in further detail with reference to examples.

The raw materials in the following preparation examples and examples are commercially available, and the raw materials listed in table 1 can be selected.

TABLE 1

Preparation example 1

A modified silicon dioxide is prepared by the following steps:

the method comprises the following steps: grinding 1kg of silicon dioxide into powder with the mesh number of 5000 meshes, burning the silicon dioxide at the burning temperature of 200 ℃ for 3h, cooling to room temperature, burning the silicon dioxide, keeping the burning temperature at 150 ℃ for 1h, putting the burned silicon dioxide in water, keeping the temperature of the water at 20 ℃, and separating and drying to obtain silicon dioxide powder; step two: mixing xanthan gum and polyvinyl alcohol in a ratio of 1: 10, adding the silicon dioxide powder obtained in the step one, wherein the weight of xanthan gum is 5% of that of the silicon dioxide powder, adding water into the mixture to immerse the mixture in the water, performing microwave treatment for 20min, adding sodium dodecyl sulfate accounting for 2% of the weight of the silicon dioxide powder and 0.5% of sodium methylene naphthalene sulfonate into the solution, performing ultrasonic treatment for 30min, and separating and drying to obtain the modified silicon dioxide.

Preparation example 2

A modified silicon dioxide is prepared by the following steps:

the method comprises the following steps: grinding 1kg of silicon dioxide into powder with 8000 meshes, burning the silicon dioxide at 500 ℃ for 1h, cooling to room temperature, burning at 100 ℃ for 3h, placing the burned silicon dioxide in water, keeping the temperature of the water at 30 ℃, and separating and drying to obtain silicon dioxide powder; step two: mixing xanthan gum and polyvinyl alcohol in a ratio of 1: 20, adding the silicon dioxide powder obtained in the step one, wherein the weight of xanthan gum is 10% of that of the silicon dioxide powder, adding water into the mixture to immerse the mixture in the water, performing microwave treatment for 10min, adding sodium dodecyl sulfate and sodium methylene naphthalene sulfonate into the solution, the weight of the sodium dodecyl sulfate is 1% of that of the silicon dioxide powder, performing ultrasonic treatment for 45min, and separating and drying to obtain the modified silicon dioxide.

Preparation example 3

A modified silicon dioxide is prepared by the following steps:

the method comprises the following steps: grinding 1kg of silicon dioxide into 6000-mesh powder, burning the silicon dioxide at 350 ℃ for 2h, cooling to room temperature, burning the silicon dioxide, keeping the temperature of water at 25 ℃, and separating and drying to obtain silicon dioxide powder; step two: mixing xanthan gum and polyvinyl alcohol in a ratio of 1: 15, adding the silicon dioxide powder obtained in the step one, wherein the weight of xanthan gum is 8% of that of the silicon dioxide powder, adding water into the mixture to immerse the mixture in the water, performing microwave treatment for 15min, adding sodium dodecyl sulfate accounting for 1.2% of the weight of the silicon dioxide powder and 0.8% of sodium methylene naphthalene sulfonate into the solution, performing ultrasonic treatment for 40min, and separating and drying to obtain the modified silicon dioxide.

Preparation example 4

A modified acrylic resin is prepared by the following steps:

mixing 1kg of acrylic resin and 2kg of perchloroethylene resin, placing the mixture in water, adding 20g of alkylphenol polyoxyethylene, carrying out ultrasonic treatment for 10min, then adding 5 times of kg of water, uniformly stirring, standing for 2h, then adding 10g of mannan, stirring for 10min, heating to 55 ℃, keeping for 1h, cooling to room temperature, separating and drying to obtain the modified acrylic resin.

Preparation example 5

A modified acrylic resin is prepared by the following steps:

mixing 1kg of acrylic resin and 3kg of perchloroethylene resin, placing the mixture in water, adding 50g of alkylphenol polyoxyethylene, carrying out ultrasonic treatment for 25min, then adding 3 times of kg of water, uniformly stirring, standing for 1h, then adding 30g of mannan, stirring for 15min, heating to 60 ℃, keeping for 3h, cooling to room temperature, separating and drying to obtain the modified acrylic resin.

Preparation example 6

A modified acrylic resin is prepared by the following steps:

mixing 1kg of acrylic resin and 2.5kg of perchloroethylene resin, placing the mixture in water, adding 35g of alkylphenol polyoxyethylene, carrying out ultrasonic treatment for 20min, adding 4 times of kg of water, uniformly stirring, standing for 1.5h, adding 20g of mannan, stirring for 12min, heating to 58 ℃, keeping for 2h, cooling to room temperature, separating and drying to obtain the modified acrylic resin.

Example 1

A combined pile for foundation engineering is prepared by the following steps:

the method comprises the following steps: mixing cement, filler, fly ash, water reducing agent, anti-permeability agent and reinforcing agent with the weight shown in table 2, and uniformly stirring;

step two: adding water with the weight shown in Table 2 into the mixed powder, stirring for 4min, and stirring uniformly;

step four: and maintaining for 28d to obtain the combined pile for foundation engineering.

Examples 2 to 12

A composite pile for foundation construction, which is different from example 1 in that the weight of each raw material is shown in table 2.

Example 13

The difference between the combined pile for foundation engineering and the embodiment 8 is that in the second step, the stirring time is 3min, and in the fourth step, the curing time is 20 d.

Example 14

The difference between the combined pile for foundation engineering and the combined pile in the embodiment 8 is that in the second step, the stirring time is 5min, and in the fourth step, the curing time is 30 d.

Comparative example 1

A composite pile for foundation engineering, which is different from embodiment 8 in that: no anti-penetration agent was added.

Comparative example 2

A composite pile for foundation engineering, which is different from embodiment 8 in that: as the anti-permeation agent, commercially available anti-permeation agents shown in Table 1 were used.

Comparative example 3

A composite pile for foundation engineering, which is different from embodiment 8 in that: the silicon dioxide in the anti-permeability agent is unmodified silicon dioxide.

Comparative example 4

A composite pile for foundation engineering, which is different from embodiment 8 in that: modified silicon dioxide is not added in the anti-permeability agent.

TABLE 2

Performance test

1. And (3) testing the compressive strength: the composite piles for foundation engineering prepared in examples 1 to 14 and comparative examples 1 to 4 were subjected to 7d and 28d compressive strength tests according to the test methods described in GB/T50080-2002, and the test data are shown in Table 3.

2. And (3) testing the breaking strength: the fabricated piles for foundation engineering prepared in examples 1 to 14 and comparative examples 1 to 4 were subjected to flexural strength tests according to the test method described in GB/T50080-2002, and the test data are shown in Table 3.

3. And (3) testing the impermeability: the composite piles for foundation engineering prepared in examples 1 to 14 and comparative examples 1 to 4 were subjected to impermeability test according to the test method described in GB/T50080-2002, and the test data are shown in table 3.

TABLE 3

As can be seen from table 3, in examples 1 to 14, compared with comparative example 1, the permeation resistance strength of the composite pile can be effectively improved by adding the permeation resistance agent, and the compressive strength and the flexural strength of the rest of the materials in the cement can be effectively combined while the permeation resistance strength is ensured to be improved.

As can be seen from table 3, the permeation resistant agents described in this example are better in permeation resistance than the commercially available permeation resistant agents in examples 1 to 14 compared to comparative example 2. In addition, the mechanical properties of the combined pile are slightly reduced after the common anti-permeability agent is added. But after the anti-permeability agent is added, the compressive strength and the anti-permeability strength of the combined pile can be improved.

As can be seen from table 3, examples 1 to 14 can enhance partial impermeability and, in addition, can improve mechanical properties of the permeation resistant agent, compared to comparative example 3, when only ordinary silica is used in the permeation resistant agent. However, the compressive strength and the impermeability strength of the composite pile can be improved after the anti-permeability agent is added.

As can be seen from table 3, examples 1 to 14 can enhance partial impermeability and can also improve mechanical properties of the permeation resistant agent, in addition to enhancing the permeation resistant ability when only the common acrylic resin is used as the permeation resistant agent, as compared with comparative example 3. However, the compressive strength and the impermeability strength of the composite pile can be improved after the anti-permeability agent is added.

As can be seen from Table 3, in examples 1-2 and 3-4, compared with example 5, when the modified silica prepared in preparation example 3 is used, the mechanical properties and the impermeability of the composite pile are better. In addition, in examples 3 to 5, compared with examples 6 to 8, when the polyacrylic resin prepared in preparation example 9 was used as the acrylic resin, the mechanical properties and the impermeability of the composite pile were better. Compared with the example 8, when the weight ratio of the modified silicon dioxide to the modified acrylic resin is 2:1, the mechanical property and the impermeability of the prepared composite pile are better. Compared with the embodiment 8, in the embodiments 11 to 12, when the weight ratio of the water reducing agent to the anti-permeability agent is 1:3, the water used by the prepared composite pile is moderate, and the mechanical property and the anti-permeability performance of the composite pile are good. Examples 13-14 compare example 8 with example 8, when the composite pile was prepared in the manner of example 8, the performance of the prepared composite pile was better. In addition, in the preparation process, after the step parameters are changed, the performance of the prepared combined pile is basically unchanged, so that the requirements on the steps can be reduced in the preparation process, and the adaptability is wider.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The utility model provides a composite pile that foundation engineering used which characterized in that: the feed is prepared from the following raw materials in parts by weight:

cement of 250 portions and 300 portions;

850 portions of filler and 950 portions;

40-60 parts of fly ash;

3-6 parts of a water reducing agent;

8-16 parts of an anti-permeability agent;

6-10 parts of a reinforcing agent;

170 portions of water and 190 portions of water;

the anti-permeability agent is composed of modified silicon dioxide and modified acrylic resin, and the modified silicon dioxide is prepared by the following method:

step two: mixing xanthan gum and polyvinyl alcohol in a ratio of 1: (10-20), adding the silicon dioxide powder obtained in the step one, wherein the weight of xanthan gum is 5-10% of that of the silicon dioxide powder, adding water into the mixture, immersing the mixture in the water, performing microwave treatment for 10-20min, adding sodium dodecyl sulfate and sodium methylene naphthalene sulfonate into the solution, wherein the weight of the sodium dodecyl sulfate is 1-2% of that of the silicon dioxide powder, performing ultrasonic treatment for 30-45min, and separating and drying to obtain modified silicon dioxide;

the modified acrylic resin is prepared by the following method:

2. A composite pile for foundation engineering according to claim 1, wherein: the weight ratio range of the modified silicon dioxide to the modified acrylic resin is (1-3): 1.

3. a composite pile for foundation engineering according to claim 1 or 2, wherein: the weight ratio range of the water reducing agent to the anti-permeability agent is 1: (2-4).

4. A composite pile for foundation engineering according to claim 1 or 2, wherein: the reinforcing agent is polypropylene fiber, and the length of the polypropylene fiber is 1-10 mm.

5. A composite pile for foundation engineering according to claim 1 or 2, wherein: the water reducing agent is a polycarboxylic acid water reducing agent.

6. A composite pile for foundation engineering according to claim 1 or 2, wherein: the filler is sand stone, and the particle size of the sand stone is 0.08-2 mm.

7. The method for preparing a composite pile for foundation engineering of any one of claims 1 to 6, comprising the steps of: