Adjustable air permeability concrete and method for preparing the same

Abstract

The present application relates to the field of new building materials, in particular to a kind of concrete with adjustable air permeability and a preparation method thereof.The concrete with adjustable air permeability provided by the present application includes concrete, inorganic binder, mineral particles, pore regulator, carbon nanotube and synthetic fiber.The concrete with adjustable air permeability is prepared by adding pore regulator, carbon nanotube and synthetic fiber at a certain temperature based on concrete, inorganic binder and mineral particles as base material.The present application also provides a preparation method of the concrete with adjustable air permeability, which includes two steps of S1 base material mixing and S2 concrete with adjustable air permeability preparation.The concrete produced by the preparation method has pore regulator uniformly distributed inside, and a thin layer of carbon nanotube fiber is generated on the surface, so that the air permeability can be adjusted by the combination of the two.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new building materials, in particular to a kind of concrete with adjustable air permeability and a preparation method thereof. BACKGROUND

[0002] In today's rapidly changing building technology, the pursuit of indoor environmental comfort in modern architecture has reached an unprecedented height. Most of the existing concrete materials on the market, although excellent in structural strength, have obvious shortcomings in air permeability, especially in humid environments. Due to the lack of good air permeability of these materials, moisture is difficult to effectively discharge, which in turn causes a series of problems such as indoor dampness and mold growth, not only threatening the structural safety of buildings, but also significantly shortening the service life of buildings and seriously affecting the overall comfort of the indoor environment.

[0003] To solve this problem, the industry has begun to develop building materials with better air permeability to improve the indoor environment. However, existing air permeable building materials generally have fixed air permeability, which cannot automatically adjust their air permeability according to changes in environmental conditions, making it difficult to meet the diverse needs of air permeability in different seasons and climate conditions. This limitation undoubtedly limits the flexibility and adaptability of building materials in practical applications.

[0004] Therefore, it is necessary to develop a kind of concrete material that can automatically adjust its air permeability according to changes in environmental humidity. This new type of concrete not only effectively addresses moisture problems and improves indoor environmental comfort, but also ensures structural strength while providing building materials with higher intelligence and self-adaptability, bringing revolutionary breakthroughs to the modern construction field. SUMMARY

[0005] To solve the above-mentioned technical problems, the present application provides a kind of concrete with adjustable air permeability and a preparation method thereof. The concrete with adjustable air permeability prepared by this method can automatically adjust its air permeability according to changes in environmental humidity while ensuring structural strength, thereby increasing the service life of buildings.

[0006] The present application discloses a kind of concrete with adjustable air permeability, including the following weight parts components:

[0007] 35-50 parts of concrete;5-7 parts of inorganic binder;5-6 parts of mineral particles;3-5 parts of air hole regulator;8-11 parts of carbon nanotube;5-8 parts of synthetic fiber.

[0008] Preferably, the inorganic binder is a silicate.

[0009] Preferably, the mineral particles are mineral materials with high porosity, further selected from quartz, bentonite and calcareous minerals.

[0010] Preferably, the air hole regulator is expanded microspheres, ultrafine silica fume or a combination thereof.

[0011] Preferably, the diameter of the carbon nanotube is 10-50 nm and the length is 20-100 μm.

[0012] The application further discloses a preparation method of the concrete with adjustable air permeability.

[0013] S1, mixing of the base material: the concrete, the inorganic binder and the mineral particles are sequentially added into a mixer for stirring, and the base material mixture is obtained after uniform stirring;

[0014] S2, preparation of the concrete with adjustable air permeability: the base material mixture obtained in the step S1 is added into a reactor, then the air hole regulator is added, the temperature is raised and the stirring is performed, then the pretreated carbon nanotube, the synthetic fiber and the water are added, the reactor containing the reaction solution is placed on an ultrasonic vibrator for ultrasonic vibration after the addition is completed, and the concrete with adjustable air permeability is obtained after the ultrasonic vibration is finished, the reactor is removed, the reaction solution is poured and formed, and the solidification treatment is performed.

[0015] Preferably, in the step S1 of mixing of the base material, the stirring speed of the mixer is 1500-2500 rpm.

[0016] Preferably, in the step S2 of preparation of the concrete with adjustable air permeability, the temperature is raised to 45-50 ℃ and the stirring is performed for 20-40 minutes in the process of temperature rising and stirring.

[0017] Preferably, in the step S2 of preparation of the concrete with adjustable air permeability, the ultrasonic frequency of the ultrasonic vibrator is 33-60 kHz, the ultrasonic vibration time is 15-30 min, the reactor is heated during the ultrasonic vibration, and the heating temperature is 35-45 ℃.

[0018] Preferably, the change range of the air permeability of the concrete with adjustable air permeability is 9-75 %.

[0019] Compared with the prior art, the application has the following beneficial effects:

[0020] The application provides a kind of concrete with adjustable air permeability and a preparation method thereof.The raw materials include concrete, inorganic binder, mineral particles, pore regulator, carbon nanotubes and synthetic fibers.The concrete with adjustable air permeability is prepared by adding the pore regulator, carbon nanotubes and synthetic fibers at a certain temperature after taking the concrete, inorganic binder and mineral particles as the base material.The carbon nanotubes and synthetic fibers form a thin layer of carbon nanotube fibers in the base material, and the surface structure can be fine-tuned according to changes in environmental humidity, temperature and other factors to change the air permeability of the material.The pore regulator is uniformly mixed in the base material, and the internal pore structure changes when the humidity and temperature change, which also affects the air permeability.In particular, when the air humidity is high, the pores in the concrete will expand, driving the surface carbon nanotube fiber thin layer to expand, thereby increasing the air permeability;when the humidity is low, the pores in the concrete will shrink, driving the surface carbon nanotube fiber thin layer to shrink, thereby reducing the air permeability.

[0021] The concrete with adjustable air permeability provided by the application also has excellent strength and corrosion resistance, is energy-saving and environmentally friendly, and can meet the long-term use requirements of buildings. DETAILED DESCRIPTION

[0022] The following examples are provided to better further understand the application and are not limited to the best mode, and do not limit the content and scope of protection of the application.Anyone who obtains any product the same as or similar to the application under the inspiration of the application or by combining the application with other prior art features falls within the scope of protection of the application.

[0023] If the specific experimental steps or conditions are not specified in the examples, the operation or conditions can be performed according to the conventional experimental steps described in the literature in the art.If the reagent or instrument is not specified by the manufacturer, it is a conventional reagent product that can be obtained by purchase.

[0024] Example 1: A kind of concrete with adjustable air permeability, which is composed of the following ingredients by weight:

[0025] Concrete 35 parts; cement 5 parts; quartz 5 parts; expanded microspheres 3 parts; carbon nanotubes 8 parts; synthetic fibers 5 parts.

[0026] A preparation method of a kind of concrete with adjustable air permeability, comprising the following steps:

[0027] S1 base material mixing: concrete, cement and quartz are added to a mixer in sequence and stirred, the stirring speed of the mixer is 1500 rpm, and a base material mixture is obtained after uniform stirring;

[0028] S2 preparation of the concrete with adjustable air permeability: add the base material mixture obtained in step S1 into a reactor, then add the expanded microspheres, and raise the temperature of the reactor to 45°C and stir for 20 minutes. Subsequently, add the pretreated carbon nanotubes, synthetic fibers, and water, wherein the volume ratio of the mixture to water is 1:1, the diameter of the carbon nanotubes is 10 nm, and the length is 20 μm. After the addition is completed, place the reactor containing the reaction solution on an ultrasonic vibrator to perform ultrasonic vibration, the ultrasonic frequency of the ultrasonic vibrator is 33 kHz, the ultrasonic vibration time is 15 min, the ultrasonic vibration needs to heat the reactor, and the heating temperature is 35°C. After the ultrasonic vibration is completed, remove the reactor, pour the reaction solution into a mold, and perform curing treatment to obtain the concrete with adjustable air permeability.

[0029] Example 2: a concrete with adjustable air permeability, comprising the following components in parts by weight:

[0030] concrete 42 parts; cement 6 parts; quartz 5.5 parts; expanded microspheres 4 parts; carbon nanotubes 9.5 parts; synthetic fibers 6.5 parts.

[0031] A preparation method of a concrete with adjustable air permeability, comprising the following steps:

[0032] S1 base material mixing: add the concrete, cement, and quartz into a mixer in sequence for stirring, the stirring speed of the mixer is 2000 rpm, and a base material mixture is obtained after uniform stirring;

[0033] S2 preparation of the concrete with adjustable air permeability: add the base material mixture obtained in step S1 into a reactor, then add the expanded microspheres, and raise the temperature of the reactor to 47°C and stir for 30 minutes. Subsequently, add the pretreated carbon nanotubes, synthetic fibers, and water, wherein the volume ratio of the mixture to water is 1:2, the diameter of the carbon nanotubes is 30 nm, and the length is 50 μm. After the addition is completed, place the reactor containing the reaction solution on an ultrasonic vibrator to perform ultrasonic vibration, the ultrasonic frequency of the ultrasonic vibrator is 46 kHz, the ultrasonic vibration time is 22 min, the ultrasonic vibration needs to heat the reactor, and the heating temperature is 40°C. After the ultrasonic vibration is completed, remove the reactor, pour the reaction solution into a mold, and perform curing treatment to obtain the concrete with adjustable air permeability.

[0034] Example 3: a concrete with adjustable air permeability, comprising the following components in parts by weight:

[0035] concrete 50 parts; cement 7 parts; quartz 6 parts; expanded microspheres 5 parts; carbon nanotubes 11 parts; synthetic fibers 8 parts.

[0036] A preparation method of a concrete with adjustable air permeability, comprising the following steps:

[0037] S1 base material mixing: concrete, cement and quartz are sequentially added to a mixer for stirring at a stirring speed of 2500 rpm, and a base material mixture is obtained after uniform stirring;

[0038] S2 preparation of the concrete with adjustable air permeability: the base material mixture obtained in S1 is added to a reactor, and then expanded microspheres are added. The temperature of the reactor is raised to 50°C and stirring is performed for 40 minutes. Then, pretreated carbon nanotubes, synthetic fibers and water are added, wherein the volume ratio of the mixture to water is 1:3, the diameter of the carbon nanotubes is 50 nm, and the length is 100 μm. After the addition is completed, the reactor containing the reaction solution is placed on an ultrasonic vibrator for ultrasonic vibration. The ultrasonic frequency of the ultrasonic vibrator is 60 kHz, and the ultrasonic vibration time is 30 min. The reactor is heated during ultrasonic vibration, and the heating temperature is 45°C. After ultrasonic vibration is completed, the reactor is removed, and the reaction solution is cast and molded and subjected to curing treatment to obtain the concrete with adjustable air permeability.

[0039] Example 4: The cement in Example 2 is replaced by talc powder; the remaining raw material components and preparation steps and conditions are the same as those in Example 2.

[0040] Example 5: The cement in Example 2 is replaced by kaolinite powder; the remaining raw material components and preparation steps and conditions are the same as those in Example 2.

[0041] Example 6: The quartz in Example 4 is replaced by bentonite; the remaining raw material components and preparation steps and conditions are the same as those in Example 4.

[0042] Example 7: The quartz in Example 4 is replaced by calcareous minerals; the remaining raw material components and preparation steps and conditions are the same as those in Example 4.

[0043] Example 8: The expanded microspheres in Example 6 are replaced by ultra-fine silicon powder; the remaining raw material components and preparation steps and conditions are the same as those in Example 6.

[0044] Example 9: The expanded microspheres in Example 6 are replaced by a mixture of ultra-fine silicon powder and expanded microspheres, wherein the mass ratio of the ultra-fine silicon powder to the expanded microspheres is 3:1; the remaining raw material components and preparation steps and conditions are the same as those in Example 6.

[0045] Example 10: The carbon nanotubes and synthetic fibers in Example 9 are removed; the remaining raw material components and preparation steps and conditions are the same as those in Example 9.

[0046] The concrete with adjustable air permeability prepared in Examples 1-10 is detected for air permeability in environments with humidity (RH) of 20%, 50% and 80%, and the detection data are shown in the following table:

[0047]

[0048] As shown by the detection data in the above table, the raw material component ratio and the parameters in the preparation method are screened in Examples 1-3, in which the air permeability adjustment of Example 2 is the best; Examples 2, 4 and 5 are screening of the inorganic binder in the raw material, and the silicate can increase the air permeability of the finished concrete, in which the adjustment performance is the best when the silicate is talc; Examples 4, 6 and 7 are screening of the mineral particles in the raw material, and the mineral material with high porosity can increase the air permeability of the finished concrete, in which the adjustment performance is the best when the mineral material is bentonite; Examples 6, 8 and 9 are screening of the pore adjuster in the raw material, and the pore adjuster can increase the air permeability of the finished concrete, in which the adjustment performance is the best when the pore adjuster is a mixture of ultra-fine silica powder and expanded microspheres; Example 10 does not add carbon nanotubes and synthetic fibers to the raw material, and it can be clearly seen that the air permeability adjustment performance of the concrete prepared in Example 10 is poor. This is because the surface of the concrete prepared in Example 10 does not form a thin layer of carbon nanotube fibers, so it cannot fine-tune according to changes in environmental humidity, temperature, etc. to change the air permeability of the material.

[0049] The air permeability-adjustable concrete prepared in Example 9 was subjected to strength and corrosion resistance detection, and the detection results are shown in the following table:

[0050]

[0051]

[0052] As can be seen from the above table, the air permeability-adjustable concrete prepared in Examples 1-9 has high compressive strength and good corrosion resistance, and is suitable for many fields.

[0053] Obviously, the above examples are only examples for clarity and do not limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those of ordinary skill in the art. Here, it is not necessary and impossible to exhaust all embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. An air-entrainable concrete, characterized by, consists of the following ingredients by weight: concrete 35~50 parts; inorganic binder 5~7 parts; mineral particles 5~6 parts; pore adjuster 3~5 parts; carbon nanotubes 8~11 parts; synthetic fibers 5~8 parts; the pore adjuster consists of expanded microspheres and ultra-fine silica powder; wherein the mass ratio of ultra-fine silica powder to expanded microspheres is 3:1; the carbon nanotubes and synthetic fibers synergistically form a fiber thin layer, and the fiber thin layer cooperates with the pore adjuster to achieve environmental humidity-responsive air permeability adjustment; the air permeability adjustment achieves an air permeability change range of 9~75% of the concrete in the range of 20%-80% of the environmental humidity.

2. The air-entraining concrete according to claim 1, wherein The inorganic binder is a silicate.

3. The air-entraining concrete according to claim 1, wherein The mineral particles are a mineral material with high porosity, and the mineral material with high porosity is any one of quartz, bentonite, and calcareous minerals.

4. The air-entraining concrete according to claim 1, wherein The diameter of the carbon nanotubes is 10~50nm, and the length is 20~100μm.

5. A method of producing the air-permeability-adjustable concrete according to claim 1, characterized by, The method comprises the following steps: S1 substrate mixing: adding concrete, inorganic binder and mineral particles to a mixer in sequence for stirring, and obtaining a substrate mixture after uniform stirring; S2 preparation of air-permeability-adjustable concrete: adding the substrate mixture obtained in S1 to a reactor, then adding a pore adjuster, heating and stirring, subsequently adding pretreated carbon nanotubes, synthetic fibers and water, removing the reactor after the addition is completed, pouring the reaction liquid into a mold and performing curing treatment to obtain air-permeability-adjustable concrete.

6. The method of claim 5, wherein the air-entraining agent is added to the concrete mixture in an amount of 0.01 to 0.1% by weight of the cement. In the S1 substrate mixing step, the stirring speed of the mixer is 1500~2500rpm.

7. The method of claim 5, wherein the air-entraining agent is added to the concrete mixture in an amount of 0.01 to 0.1% by weight of the cement. In the S2 air-permeability-adjustable concrete preparation step, the temperature needs to be raised to 45~50℃ and stirred for 20~40 minutes during the heating and stirring process.

8. The method of claim 5, wherein the air-entraining agent is added to the concrete mixture in an amount of 0.01 to 0.1% by weight of the cement. In the S2 air-permeability-adjustable concrete preparation step, the ultrasonic frequency of the ultrasonic vibrator is 33~60kHz, the ultrasonic vibration time is 15~30min, and the reactor needs to be heated during ultrasonic vibration, and the heating temperature is 35~45℃.

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