Preparation equipment and method of cement sol slurry
By using immersive ultrasonic vibration and stirring devices in cement slurry, the solubility and dispersion of cement particles are improved, and the problem of insufficient solubility of cement particles in cement slurry is solved, which significantly improves the strength and permeability of concrete, and reduces pores and Dry shrinkage phenomenon.
Patent Information
- Application Number
- CN202411721150.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-01-10
AI Technical Summary
In the prior art, the cement particles in cement slurry are insufficient, resulting in low concrete strength, many pores and poor permeability, and conventional prehydration methods cannot effectively solve this problem.
The cement sol slurry preparation equipment including an immersive ultrasonic vibration device and agitating device is adopted to vibrate and stir the cement slurry through an ultrasonic frequency of 14-41kHz and an ultrasonic power density of 0.002-0.04W/cm3 to improve the solubility and dispersion of cement particles. to form a high content of cement sol slurry.
It significantly improves the strength and bonding strength of concrete, reduces pores and dry shrinkage, avoids later strength retracting, and improves the overall performance of concrete.
Smart Images
Figure CN119283196A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of concrete preparation, in particular to a device and a method for preparing cement slurry with sol properties. Background Art
[0002] Cement is mixed with water to make cement paste, and cement paste is mixed with aggregate to make concrete. The sol formed by the dissolution of cement particles in the cement paste in water is the adhesive in the concrete that binds the aggregates together. The conventional process from preparing cement paste to mixing concrete is a continuous process or a process with a short interval, usually not more than 5 minutes. Since cement is a silicate mineral particle, its dissolution rate is relatively slow. Many research results show that the process of complete dissolution and hydration of cement particles can take as long as 1 year to several decades. Therefore, the sol content in the cement paste when mixing concrete by the conventional process is relatively low. This cement paste is essentially just a suspension of cement particles containing a small amount of sol. The sol content in the cement paste that plays a gelling role is thin, which affects the development of concrete strength after molding and hardening. In addition, the cement paste suspension contains a large amount of excess water that does not participate in hydration. After evaporation, a large number of tiny pores will be formed, which will not only affect the development of concrete strength but also cause the concrete to shrink and deteriorate in impermeability.
[0003] In order to improve the problem of insufficient solubility of cement particles in cement slurry, the cement slurry can be prehydrated at present, that is, the cement slurry is stirred by a high-speed mixer to accelerate the dissolution of cement particles. However, since the speed of the cement slurry high-speed mixer usually does not exceed 20r / s, that is, 1200r / min, and is limited by the setting time of cement, the initial setting time of ordinary silica cement is about 150 to 200 minutes, and it cannot be stirred at high speed for a long time, so it cannot effectively solve the problem of insufficient dissolution of cement particles. Therefore, the cement slurry prehydrated by high-speed stirring is still a cement particle suspension containing only a small amount of sol, and its effect is very limited. Therefore, this method is basically not used in concrete production. There are also some studies that prehydrate cement slurry for a long time, and the prehydration time can be up to several days. At this time, the cement sol in the cement slurry has solidified to form gel and crystals, and cannot be used directly to mix concrete. It can only be used as a "seed" in small amounts, usually not more than 3% of the total cement slurry, and added to the newly mixed cement slurry. Because the mechanism explanation of this method is still incomplete, it is only used in laboratory research and has basically not been applied in actual production. Some studies have also used ultrasonic high-frequency vibration to homogenize cement paste or concrete to improve the dispersion of cement particles, but the implementation time is usually no more than 5 minutes, and it can only disperse the cement particles in the concrete to a certain extent, that is, the homogenization effect.
[0004] At present, the hydration degree of cement particles in cement paste obtained by the above method is less than 15%, and it is essentially still a suspension of cement particles. Mixing concrete with it leads to a variety of recognized concrete microstructural defects. Summary of the invention
[0005] In order to solve the problems existing in the prior art, the present invention provides a preparation device and method of cement sol slurry, aiming to improve the strength of concrete and reduce the shrinkage of concrete without affecting the later strength development of concrete.
[0006] According to one aspect of the present invention, there is provided a preparation device for cement sol slurry, comprising: A stirring container, wherein the stirring container has an opening, and an openable and closable cover is disposed on the opening; An immersion type ultrasonic vibration device, wherein the immersion type ultrasonic vibration device is disposed through the cover body; A stirring device, the stirring device is arranged in the stirring container at a side away from the immersion ultrasonic vibration device; an ultrasonic transducer, the ultrasonic transducer is arranged on the outer wall of the stirring container.
[0007] As a preferred embodiment of a cement sol slurry preparation device of the present invention, the preparation device also includes a lifting device for lifting the cover body, the lifting device also includes a lifting motor and a lifting rod, one end of the lifting rod is connected to the cover body, and the other end of the lifting rod is connected to the lifting motor.
[0008] As a preferred embodiment of a cement sol slurry preparation device of the present invention, the stirring device includes a stirring motor and a stirring shaft arranged outside a stirring container, one end of the stirring shaft is connected to the stirring motor, and the other end passes through the wall of the stirring container and extends into the cavity of the stirring container, and a stirring blade is arranged on the other end of the stirring shaft.
[0009] As a preferred embodiment of the cement sol slurry preparation equipment of the present invention, the preparation equipment also includes a control system, and the control system is electrically connected or electrically signal connected to the stirring motor, the lifting motor, the ultrasonic generator and the ultrasonic transducer.
[0010] As a preferred solution of the cement sol slurry preparation equipment of the present invention, the preparation equipment also includes a main frame, and the stirring container is arranged in the main frame.
[0011] As a preferred embodiment of the cement sol slurry preparation equipment of the present invention, the opening is located above the container, the lifting rod passes through the top of the main frame and is connected to the upper cover, and the mixing container also includes an outlet located on one side of its bottom.
[0012] As a preferred embodiment of the cement sol slurry preparation equipment of the present invention, the stirring blades include at least two groups, and an elastic scraper is installed at the lower part of the stirring blades near the bottom of the stirring container, and the scraper is in close contact with the bottom of the container. Each group of stirring blades is arranged along the radial direction of the stirring container and satisfies that the bottom area of the stirring area after all the stirring blades in the group rotate one circle is not less than 90% of the bottom area of the stirring container. The immersion ultrasonic vibration device includes at least two, which are evenly arranged along the diameter direction of the cover body, and the frequency of the immersion ultrasonic vibration device is 14-41kHz.
[0013] As a preferred embodiment of the cement sol slurry preparation device of the present invention, the ultrasonic power density of the ultrasonic transducer is 0.002-0.04W / cm 3 The frequency is 14-41kHz. The ultrasonic transducer can transmit high-frequency vibration waves through the outer wall of the stirring container to the cement slurry on the inner wall of the container, thereby compensating for the problem that the cement slurry near the inner wall of the container has weak ultrasonic intensity due to its distance from the immersion ultrasonic vibration device. In the technical solution of the present invention, the ultrasonic power density of the ultrasonic transducer is further preferably 0.002-0.02W / cm 3 This is because more than 0.02W / cm 3 After the power density reaches a certain level, its effect will tend to saturation.
[0014] As a preferred embodiment of a cement sol slurry preparation device of the present invention, the immersion ultrasonic vibration device includes an ultrasonic vibration rod and an ultrasonic generator. The length of the ultrasonic vibration rod satisfies that when the cover is closed on the stirring container, the length of the rod extending into the cement slurry is not less than 1 / 2 of the height of the cement slurry.
[0015] According to another aspect of the present invention, a method for preparing cement sol slurry is provided, wherein the method adopts the preparation device as described above and comprises the following steps: 1) adding raw materials into the mixing container, wherein the raw materials include water, cement and a water reducing agent, and controlling the lifting motor to cover the cover plate on the mixing container; 2) Turn on the immersed ultrasonic vibration device to vibrate the cement slurry at a frequency of 14-41kHz, set the ultrasonic transducer frequency to 14-41kHz and the ultrasonic power density to 0.002-0.04W / cm 3 The cement slurry is subjected to ultrasonic action, and a stirring device is simultaneously turned on to stir the cement slurry at a speed of 10-30r / min, and after completion, a cement sol slurry is obtained.
[0016] As a preferred embodiment of the method for preparing cement sol slurry of the present invention, when the ambient temperature is 20-25°C, the stirring time is 10-30min, the ultrasonic action time is 10-30min, and the vibration time is 10-30min. When the ambient temperature is lower than 20°C, the stirring time, the ultrasonic action time and the vibration time are all increased by more than 5min. When the ambient temperature is higher than 25°C, the stirring time, the ultrasonic action time and the vibration time are all reduced by more than 5min.
[0017] As a preferred embodiment of the method for preparing cement sol slurry of the present invention, the ratio of water to cement is 0.4:1-0.7:1, the amount of the water reducer added is 0.1‰-2‰ of the cement, and the water reducer includes polycarboxylate water reducer powder.
[0018] According to another aspect of the present invention, a cement sol slurry is provided, wherein the cement sol slurry is prepared by the method as described above.
[0019] According to another aspect of the present invention, a cement concrete is provided, wherein the cement concrete comprises the cement sol slurry as described above.
[0020] In the technical solution of the present invention, unless otherwise specified, the unit of content (ratio) is mass.
[0021] Compared with the prior art, the present invention has the following beneficial effects: 1. Compared with the cement slurry of the prior art, the free water content in the cement sol slurry prepared by the present invention is lower, so the pores in the gel formed after solidification are less and more uniform and dense, and the bonding strength between the solidified gel and the aggregate in the cement concrete prepared by the present invention is higher, thus significantly improving the strength of the concrete. The strength of the cement concrete prepared by the present invention is more than 7% higher than that of the cement concrete prepared by ordinary cement slurry under the same ratio, and can even reach more than 10%.
[0022] 2. The cement sol slurry prepared by the present invention improves the strength of concrete by improving the microstructure of the cement slurry, so there will be no problem of strength shrinkage of concrete in the later stage.
[0023] 3. The cement sol slurry prepared by the present invention is a product of deep hydration of cement particles. The cement particles in the slurry have high solubility. Therefore, when preparing cement concrete, the chemical shrinkage produced by the late hydration process of cement particles is effectively reduced, and the shrinkage and cracking of concrete are correspondingly reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 Structural schematic diagram of cement sol slurry preparation equipment of the present invention Figure 2 Schematic diagram of the stirring device structure of the present invention Among them, 1-stirring container, 2-cover, 3-immersion ultrasonic vibration device, 301-ultrasonic generator, 302-vibration rod, 4-stirring device, 401-stirring motor, 402-stirring shaft, 403-stirring blade, 5-ultrasonic transducer, 6-lifting device, 601-lifting motor, 602-lifting rod, 7-main frame, 8-export DETAILED DESCRIPTION
[0025] See also Figure 1-2 In one specific embodiment of the present invention, a preparation device for cement sol slurry is provided, which comprises: A stirring container 1, wherein the stirring container has an opening, and a cover 2 that can be opened and closed is provided on the opening; A lifting device 6 is used to lift the cover 2. The lifting device 6 also includes a lifting motor 601 and a lifting rod 602. One end of the lifting rod 602 is connected to the cover 2, and the other end of the lifting rod 602 is connected to the lifting motor 601. Four immersion ultrasonic vibration devices 3 include ultrasonic vibration rods 302 and ultrasonic generators 301. The four ultrasonic vibration rods 302 are arranged at equal intervals along the diameter direction of the cover. The length of the ultrasonic vibration rods 302 is such that when the cover 2 is covered on the mixing container 1, the length of the rod extending into the cement slurry is 1 / 2 of the height of the cement slurry. In the process of preparing cement slurry, the immersion ultrasonic vibration device 3 can directly transmit high-frequency vibration waves to the cement slurry, with the highest energy transmission efficiency. After use, the immersion ultrasonic vibration device can be raised to facilitate cleaning of the mixing tank.
[0026] A stirring device 4, the stirring device 4 is arranged in the stirring container 1 on a side away from the immersion ultrasonic vibration device 3, the stirring device 4 includes a stirring motor 401 and a stirring shaft 402 arranged on the outside of the bottom of the stirring container, one end of the stirring shaft 402 is connected to the stirring motor 401, and the other end penetrates the wall of the stirring container 1 and extends into the cavity of the stirring container 1, and a stirring blade 403 is arranged on the other end of the stirring shaft 402, the stirring blade 403 includes two groups, and there are two stirring blades 403 on the side away from the vibration rod 302, and the stirring blades 403 are arranged on the other end of the stirring shaft 402. A plastic or rubber elastic scraper is installed at the bottom, and the scraper contacts the bottom of the stirring container so as to scrape up the cement deposited at the bottom of the container, so that it can undergo a sol reaction better and improve the sol formation effect. There are three stirring blades 403 near the side of the vibrating rod 301, and a distance of 3 cm is maintained from the end of the vibrating rod 301 to prevent collision and damage to components during the stirring process. Each group of stirring blades 403 is arranged along the radial direction of the stirring container and meets the requirement that the bottom area of the stirring area after all stirring blades 403 of the group rotate one circle is 98% of the bottom area of the stirring container. In the process of preparing cement slurry, the stirring device 4 can scrape up the cement slurry in the bottom area of the stirring container to prevent the heavier cement particles in the cement slurry from being deposited at the bottom, thereby reducing the ultrasonic stirring efficiency.
[0027] The ultrasonic transducer 5 is arranged on the outer wall of the stirring container 1. In the process of preparing cement slurry, the ultrasonic transducer 5 can transmit high-frequency vibration waves to the cement slurry on the inner wall of the container through the outer wall of the stirring container, so as to compensate for the problem that the cement slurry near the inner wall of the container has weak ultrasonic intensity due to being far away from the immersion ultrasonic vibration device.
[0028] When preparing cement sol slurry, water, water reducer and cement are added to a stirring container, wherein the ratio of water to cement is 0.4:1, and the amount of the water reducer added is 1‰ of the cement. The purpose of adding the water reducer in the present invention is to make the cement slurry liquefied better and enhance the effect of ultrasonic treatment. There is no special requirement for the type of water reducer. The water reducers disclosed in the prior art are all suitable for the scheme of the present invention. In this embodiment, polycarboxylic acid water reducer powder is selected as the water reducer. Then the cover is lowered, and the ultrasonic vibration rod is immersed in the cement slurry. The ultrasonic vibration device is started to vibrate the cement slurry at a frequency of 15kHz, and the power density of the ultrasonic transducer is set to 0.02W / cm 3 (The power of the ultrasonic transducer is obtained by multiplying the volume of the cement slurry in the container by the power density, the same below), the cement slurry is subjected to ultrasonic action at a frequency of 15kHz, the stirring device is started to stir the cement slurry at a speed of 10r / min, and at an ambient temperature of 25°C, ultrasound, vibration and stirring are carried out simultaneously, each for 10 minutes, and cement sol slurry is obtained after completion.
[0029] The cement sol slurry is mixed in a ratio of cement sol slurry: sand: gravel = 1.45:2.0:3.9, and then stirred evenly to obtain cement sol slurry concrete.
[0030] After testing, the compressive and flexural strengths of concrete made of cement sol slurry were 35.7MPa and 12.4MPa at the age of 1-28 days, which were 10.3% and 9.4% higher than those of concrete made of cement slurry (the ratio of water to cement was 0.4:1, the amount of water reducer added was 1‰ of cement, and the mixture was stirred): sand: gravel = 1.45:2.0:3.9, and no strength shrinkage phenomenon or surface shrinkage cracks were found at the age of 90 days.
[0031] In another specific embodiment of the present invention, the process parameters used in preparing the cement sol slurry are: the frequency of the ultrasonic vibration device is 28 kHz, the power density of the ultrasonic transducer is 0.002 W / cm 3 , frequency is 28kHz, the speed of the stirring device is 30r / min; the ambient temperature is 25℃, ultrasound, vibration and stirring are carried out simultaneously, and the time is 20min.
[0032] The cement sol slurry is mixed in a ratio of cement sol slurry: sand: gravel = 1.5:1.9:3.8, and then stirred evenly to obtain cement sol slurry concrete.
[0033] After testing, the compressive and flexural strengths of concrete made of cement sol slurry were 41.6MPa and 14.2MPa at the age of 1-28 days, which were 8.9% and 7.3% higher than those of concrete made of cement sol slurry (the ratio of water to cement was 0.4:1, the amount of water reducer added was 1‰ of cement, and the mixture was stirred): sand: gravel = 1.5:1.9:3.8, and no strength shrinkage phenomenon or surface shrinkage cracks were found at the age of 90 days.
[0034] In another specific embodiment of the present invention, the process parameters used in preparing the cement sol slurry are: the frequency of the ultrasonic vibration device is 40 kHz; the power density of the ultrasonic transducer is 0.01 W / cm 3 , frequency is 40kHz, the speed of the stirring device is 15r / min; the ambient temperature is 25℃, ultrasound, vibration and stirring are carried out simultaneously, and the time is 30min.
[0035] The cement sol slurry is mixed in a ratio of cement sol slurry: sand: gravel = 1.4:1.95:3.8, and then stirred evenly to obtain cement sol slurry concrete.
[0036] After testing, the compressive and flexural strengths of concrete made of cement sol slurry were 42.3MPa and 14.5MPa at the age of 1-28 days, which were 11.8% and 9.6% higher than those of concrete made of cement sol slurry (the ratio of water to cement was 0.4:1, the amount of water reducer added was 1‰ of cement, and the mixture was stirred): sand: gravel = 1.4:1.95:3.8, and no strength shrinkage phenomenon or surface shrinkage cracks were found at the age of 90 days.
[0037] In another specific embodiment of the present invention, the preparation equipment also includes a control system (not shown in the figure), which is electrically connected to the stirring motor 401, the lifting motor 601, the ultrasonic generator 301 and the ultrasonic transducer 5 or connected by electrical signals (such as WiFi, Bluetooth, 3G, 4G, 5G) to achieve remote control when preparing cement sol slurry.
[0038] In another specific embodiment of the present invention, the preparation equipment also includes a main frame 7, the stirring container 1 is arranged in the main frame 7, the opening is located above the container, the lifting rod 602 passes through the top of the main frame 7 and is connected to the upper cover, and the stirring container 1 also includes an outlet 8 located on one side of its bottom.
[0039] It should be noted that, according to the above embodiments of the present invention, those skilled in the art can fully realize the full scope of the independent claims and dependent rights of the present invention, and the implementation process and method are the same as the above embodiments; and the part not described in detail in the present invention belongs to the well-known technology in the field. However, the protection scope of the present invention is not limited to this, and any changes or substitutions that can be easily thought of by any person familiar with the field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.
Claims
1. A cement sol slurry preparation device, characterized in that: include: A stirring container, wherein the stirring container has an opening, and an openable and closable cover is disposed on the opening; An immersion type ultrasonic vibration device, wherein the immersion type ultrasonic vibration device is disposed through the cover body; A stirring device, the stirring device is arranged in the stirring container at a side away from the immersion ultrasonic vibration device; An ultrasonic transducer is arranged on the outer wall of the stirring container.
2. The preparation device according to claim 1, characterized in that: The preparation equipment also includes a lifting device for lifting the cover body, and the lifting device also includes a lifting motor and a lifting rod, one end of the lifting rod is connected to the cover body, and the other end of the lifting rod is connected to the lifting motor.
3. The preparation device according to claim 1, characterized in that: The stirring device includes a stirring motor and a stirring shaft arranged outside the stirring container, one end of the stirring shaft is connected to the stirring motor, and the other end penetrates the wall of the stirring container and extends into the cavity of the stirring container, and a stirring blade is arranged on the other end of the stirring shaft; the preparation equipment also includes a control system, and the control system is electrically connected or electrically signal connected to the stirring motor, the lifting motor, the ultrasonic generator and the ultrasonic transducer.
4. The preparation device according to any one of claims 1 to 3, characterized in that: The preparation equipment also includes a main frame, the stirring container is arranged in the main frame, the opening is located above the container, the lifting rod passes through the top of the main frame and is connected to the upper cover, and the stirring container also includes an outlet located on one side of its bottom.
5. The preparation device according to claim 4, characterized in that: The stirring blades include at least two groups, and an elastic scraper is installed at the lower part of the stirring blades near the bottom of the stirring container. The scraper is in close contact with the bottom of the container. Each group of stirring blades is arranged along the radial direction of the stirring container and satisfies that the bottom area of the stirring area after all the stirring blades in the group rotate one circle is not less than 90% of the bottom area of the stirring container. The immersion type ultrasonic vibration device includes at least two, which are evenly arranged along the diameter direction of the cover body. The ultrasonic power density of the ultrasonic transducer is 0.002-0.04W / cm 3 , the frequency is 14-41kHz, the immersion ultrasonic vibration device includes an ultrasonic vibration rod and an ultrasonic generator, the length of the ultrasonic vibration rod is sufficient to ensure that when the cover is closed on the stirring container, the length of the rod extending into the cement slurry is not less than 1 / 2 of the height of the cement slurry.
6. A method for preparing cement sol slurry, the method adopting the preparation equipment according to any one of claims 1 to 5, characterized in that: The steps include: 1) adding raw materials into the mixing container, wherein the raw materials include water, a water reducing agent and cement, and controlling the lifting motor to cover the cover plate on the mixing container; 2) Turn on the immersed ultrasonic vibration device to vibrate the cement slurry at a frequency of 14-41kHz, set the ultrasonic transducer frequency to 14-41kHz and the ultrasonic power density to 0.002-0.04W / cm 3 The cement slurry is subjected to ultrasonic treatment, and a stirring device is turned on to stir the cement slurry at a speed of 10-30 r / min. After the stirring is completed, a cement sol slurry is obtained.
7. The preparation method according to claim 6, characterized in that: When the ambient temperature is 20-25℃, the stirring time is 10-30min, the ultrasonic action time is 10-30min, and the vibration time is 10-30min. When the environment is below 20℃, the stirring time, ultrasonic action time and vibration time are all increased by more than 5min. When the environment is above 25℃, the stirring time, ultrasonic action time and vibration time are all reduced by more than 5min.
8. The preparation method according to claim 6 or 7, characterized in that: In the step 1), the ratio of water to cement is 0.4:1-0.7:1, and the amount of the water reducing agent added is 0.1‰-2‰ of the cement.
9. A cement sol slurry, wherein the cement sol slurry is prepared by the method according to any one of claims 6 to 8.
10. A cement concrete comprising the cement sol slurry according to claim 9.