A concrete viscosity regulator, its preparation method and application
A concrete viscosity modifier was prepared by combining modified hemp stalk viscose fiber powder, biomass powder, and silica fume. This solved the problem of uneven concrete viscosity adjustment in existing technologies, and enabled rapid thickening, viscosity enhancement, and water retention of concrete, thereby improving its plasticity and strength.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LUJIANG XINCHUANG NEW MATERIAL CO LTD
- Filing Date
- 2023-06-01
- Publication Date
- 2026-08-04
AI Technical Summary
In existing technologies, when adjusting the viscosity of concrete by adding fly ash, silica fume, or thickeners, the effect is ineffective if the amount added is too small, while the effect is too large if the amount added is too large, resulting in high water bleeding rate of concrete, causing problems such as pitting, plastic cracking, and reduced strength.
A concrete viscosity modifier was prepared by using a combination of modified hemp stalk viscose fiber powder, biomass powder, and silica fume and fly ash, through hydrothermal treatment, alkali treatment, and drying and pulverizing. The biomass powder included oyster shell powder, mussel shell powder, or barnacle powder with a particle size of 50-70 μm, and the modified hemp stalk viscose fiber powder had a particle size of 40-55 μm. After ultrasonic mixing, the mixture was incorporated into the concrete.
It significantly improves the viscosity and water retention capacity of concrete, enhances the rapid thickening and viscous effect of concrete, reduces bleeding, and improves the plasticity and strength of concrete.
Smart Images
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Figure BDA0004261126520000101
Abstract
Description
Technical Field
[0001] This invention belongs to the field of concrete additives technology, specifically relating to a concrete viscosity modifier, its preparation method, and its application. Background Technology
[0002] Concrete is a general term for engineering composite materials in which aggregates are bound together by cementing materials. The term concrete usually refers to cement concrete, also known as ordinary concrete, which is made by mixing cement as cementing material, sand and stone as aggregates, and water (which may contain admixtures and additives) in a certain proportion. Concrete has the characteristics of abundant raw materials, low price and simple production process, and is therefore widely used in civil engineering.
[0003] In existing technologies, the viscosity of concrete is mostly adjusted by adding fly ash, silica fume, or thickeners. Thickeners include water-soluble cellulose polymers, water-soluble acrylic polymers, bio-glue, glucose, or sucrose polymers. Among them, cellulose ethers and methylcellulose are more commonly used. However, when added to concrete to adjust viscosity, a small amount will not have a rapid thickening and viscosity-increasing effect, while a large amount will easily lead to a high bleeding rate in the concrete, resulting in a series of problems such as pitting, plastic cracking, and reduced surface concrete strength. Summary of the Invention
[0004] The purpose of this invention is to provide a concrete viscosity modifier, its preparation method, and its application in order to solve the above-mentioned problems. It aims to address the issue that in the prior art, the viscosity of concrete is mostly adjusted by adding fly ash, silica fume, or thickeners. However, when these are added to concrete to adjust viscosity, if the amount added is too small, they will not have a rapid thickening and viscosity-increasing effect, while if the amount added is too large, it will easily lead to a high bleeding rate in the concrete, resulting in a series of problems such as pitting, plastic cracking, and reduced surface concrete strength.
[0005] The present invention achieves the above objectives through the following technical solutions:
[0006] A concrete viscosity modifier comprises the following raw materials in weight percentages: 27%–45% modified hemp stalk viscose fiber powder, 29%–53% biomass powder, 7%–15% silica fume, and 10%–20% fly ash, wherein the modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization.
[0007] As a further optimization of the present invention, the biomass powder is any one or more of oyster shell powder, mussel shell powder, and barnacle powder, and the particle size of the biomass powder is 50-70μm.
[0008] As a further optimization of the present invention, the particle size of the modified hemp stalk viscose fiber powder is 40-55 μm.
[0009] A method for preparing a concrete viscosity modifier, comprising the following specific steps:
[0010] Step 1: Place hemp stalk viscose fiber in a container and wash it 2-4 times with hot water at 70℃-80℃, each time for 30 minutes. Squeeze out the water and set aside.
[0011] Step 2: The hemp stalk viscose fiber after the hydrothermal treatment in Step 1 is soaked in an 8%-12% sodium hydroxide solution and heated to 40℃-55℃ for 2-5 hours, and then dried at 65℃ for 12 hours for later use.
[0012] Step 3: The hemp stalk viscose fiber dried in Step 2 is pulverized to obtain modified hemp stalk viscose fiber powder;
[0013] Step 4: The modified hemp stalk viscose fiber powder obtained in Step 3 is thoroughly mixed with biomass powder and silica fume in an ultrasonic treatment condition according to the mass ratio, and a certain mass ratio of fly ash is added to obtain the concrete viscosity modifier.
[0014] As a further optimization of the present invention, the ultrasonic treatment is stirring at 1200-1800 r / min for 8-15 min.
[0015] As a further optimization of the present invention, the preparation method of the biomass powder is as follows: soak the raw materials in a 6%-8% sodium hydroxide solution for 3-5 hours, take out the raw materials and dry them at 40℃-65℃ for 40-48 hours, grind and pulverize them into powder after drying, and dry the powder at 70℃ for 10-12 hours to obtain the biomass powder.
[0016] A concrete system comprising cementitious materials, aggregates and water, and a concrete viscosity modifier, wherein the concrete viscosity modifier is incorporated at an amount of 5%-10%.
[0017] As a further optimization of the present invention, the glue-to-water ratio is 1.6-2.3:1, the cementitious material includes cement, fly ash and slag powder, the cement is PP325 cement, and the aggregate includes coarse aggregate and fine aggregate with a gradation ratio of (14-26):(1-1.4).
[0018] The beneficial effects of this invention are as follows:
[0019] 1) This invention can significantly increase the viscosity of concrete by using oyster shell powder, mussel shell powder, and barnacle powder alone or in any combination, giving the concrete the ability to quickly thicken and viscous. The use of modified hemp stalk viscose fiber powder can significantly improve the water retention capacity of concrete. Furthermore, when biomass powder and modified hemp stalk viscose fiber powder are used together, after absorbing water and expanding, they fill the gaps between concrete particles, which can further improve the concrete's ability to quickly thicken and viscous and its water retention capacity.
[0020] 2) In this invention, applying barnacle powder or biomass powder containing barnacle powder to concrete has a better effect on improving the concrete's ability to quickly thicken and thicken, as well as its water retention capacity. Detailed Implementation
[0021] The present application will be further described in detail below with reference to the embodiments. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0022] I. Materials and Methods
[0023] Unless otherwise specified, the methods used in this embodiment are conventional methods known to those skilled in the art, and the reagents and materials used are commercially available products.
[0024] To investigate the effects of oyster shell powder (raw material: oyster shells), mussel shell powder (raw material: mussel shells), barnacle powder (raw material: whole barnacles), and modified hemp stalk viscose fiber powder on the viscosity and water retention properties of concrete, the following examples were set up, along with comparative examples 1-2 and a control group. The control group consisted of a concrete system without added viscosity modifiers, used as a reference.
[0025] Example 1
[0026] This embodiment provides a component formulation for a concrete viscosity modifier, comprising the following raw materials by mass percentage: 39% modified hemp stalk viscose fiber powder, 34% biomass powder, 12% silica fume, and 15% fly ash. The modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization. The biomass powder is oyster shell powder with a particle size of 50-70 μm, and the modified hemp stalk viscose fiber powder has a particle size of 40-55 μm.
[0027] A method for preparing a concrete viscosity modifier, comprising the following specific steps:
[0028] Step 1: Place hemp stalk viscose fiber in a container and wash it three times with hot water at 70℃-80℃, each time for 30 minutes. Squeeze out the water and set aside.
[0029] Step 2: The hemp stalk viscose fiber after the hydrothermal treatment in Step 1 is soaked in an 8% sodium hydroxide solution and heated to 40℃-55℃ for 3 hours, and then dried at 65℃ for 12 hours for later use.
[0030] Step 3: The hemp stalk viscose fiber dried in Step 2 is pulverized to obtain modified hemp stalk viscose fiber powder;
[0031] Step 4: Mix the modified hemp stalk viscose fiber powder obtained in Step 3 with biomass powder and silica fume in the above mass ratio under ultrasonic treatment conditions. The ultrasonic treatment is 1500 r / min and stirring for 12 min. Then add fly ash in the above mass ratio to obtain the concrete viscosity modifier.
[0032] The method for preparing the biomass powder is as follows: soak oyster shells in a 6% sodium hydroxide solution for 4 hours, remove the oyster shells and dry them at 40℃-65℃ for 45 hours, grind and pulverize them into powder, and then dry the powder at 70℃ for 12 hours to obtain the biomass powder.
[0033] Example 2
[0034] This embodiment provides a component formulation for a concrete viscosity modifier, comprising the following raw materials by mass percentage: 39% modified hemp stalk viscose fiber powder, 34% biomass powder, 12% silica fume, and 15% fly ash. The modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization. The biomass powder is mussel shell powder.
[0035] The specific preparation methods are consistent with those in Example 1.
[0036] Example 3
[0037] This embodiment provides a component formulation for a concrete viscosity modifier, comprising the following raw materials by mass percentage: 39% modified hemp stalk viscose fiber powder, 34% biomass powder, 12% silica fume, and 15% fly ash. The modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization. The biomass powder is barnacle powder.
[0038] The specific preparation methods are consistent with those in Example 1.
[0039] Example 4
[0040] This embodiment provides a component formulation for a concrete viscosity modifier, comprising the following raw materials by mass percentage: 39% modified hemp stalk viscose fiber powder, 34% biomass powder, 12% silica fume, and 15% fly ash. The modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization. The biomass powder is a mixture of oyster shell powder and mussel shell powder, wherein the mass ratio of oyster shell powder to mussel shell powder is 1:1.
[0041] The specific preparation methods are consistent with those in Example 1.
[0042] Example 5
[0043] This embodiment provides a component formulation for a concrete viscosity modifier, comprising the following raw materials by mass percentage: 39% modified hemp stalk viscose fiber powder, 34% biomass powder, 12% silica fume, and 15% fly ash. The modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization. The biomass powder is a mixture of oyster shell powder and barnacle powder, wherein the mass ratio of oyster shell powder to barnacle powder is 1:1.
[0044] The specific preparation methods are consistent with those in Example 1.
[0045] Example 6
[0046] This embodiment provides a component formulation for a concrete viscosity modifier, comprising the following raw materials by mass percentage: 39% modified hemp stalk viscose fiber powder, 34% biomass powder, 12% silica fume, and 15% fly ash. The modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization. The biomass powder is a mixture of mussel shell powder and barnacle powder, wherein the mass ratio of mussel shell powder to barnacle powder is 1:1.
[0047] The specific preparation methods are consistent with those in Example 1.
[0048] Example 7
[0049] This embodiment provides a component formulation for a concrete viscosity modifier, comprising the following raw materials by mass percentage: 39% modified hemp stalk viscose fiber powder, 34% biomass powder, 12% silica fume, and 15% fly ash. The modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization. The biomass powder is a mixture of oyster shell powder, mussel shell powder, and barnacle powder, wherein the mass ratio of the three powders is 1:1:1.
[0050] The specific preparation methods are consistent with those in Example 1.
[0051] Comparative Example 1
[0052] The modified hemp stalk viscose fiber powder in the formulation of Example 3 was replaced with silica fume by an equal mass, while the rest remained the same as in Example 3.
[0053] Comparative Example 2
[0054] The biomass powder in the formulation of Example 3 was replaced with silica fume, while the rest remained the same as in Example 3.
[0055] II. Verification Experiment
[0056] Concrete viscosity and water retention properties were tested using the concrete viscosity modifiers obtained in Examples 1-7 and Comparative Examples 1-2, in accordance with the "Test Procedures for Cement and Cement Concrete in Highway Engineering" JTG E30-2005. The concrete system consisted of cementitious materials, aggregates, and water, as well as a concrete viscosity modifier. The dosage of the concrete viscosity modifier was 5%-10%, the binder-to-water ratio was 1.6-2.3:1, the cementitious materials included cement, fly ash, and slag powder, the cement was PP325 cement, and the aggregates included coarse and fine aggregates with a gradation ratio of (14-26):(1-1.4). The concrete mix design used in this experiment is shown in Table 1 (unit: kg / cm³). 2 The mixture consisted of gravel with a particle size of 7-13 mm and sand with a particle size of 0.5-0.7 mm. With the other components maintained at a constant ratio, a concrete viscosity modifier was added at a dosage of 7% (the percentage of the concrete viscosity modifier by mass in the total mixture). The test results are shown in Table 2.
[0057] Table 1 Concrete Mixing Table
[0058] Dosage 200 770 630 175 110 235
[0059] Table 2 Test Data Table
[0060]
[0061] Experimental Conclusions: Table 1-2 shows that the use of oyster shell powder, mussel shell powder, and barnacle powder, alone or in any combination, can significantly increase the viscosity of concrete, giving it the ability to rapidly thicken and viscous. Among them, barnacle powder or biomass powder containing barnacle powder has the best effect. The use of modified hemp stalk viscose fiber powder can significantly improve the water retention capacity of concrete. When biomass powder and modified hemp stalk viscose fiber powder are used together, after absorbing water and expanding, they fill the gaps between concrete particles, further improving the ability of concrete to rapidly thicken and viscous, and further improving the water retention capacity of concrete.
[0062] To further investigate the effects of concrete viscosity modifier dosage on concrete viscosity and water retention properties, and the optimal ratio of modified hemp stalk viscose fiber powder to biomass powder, the following groups were established:
[0063] Group 1
[0064] The component formulation of the concrete viscosity modifier in Example 3 was replaced with:
[0065] The raw materials include the following percentages by weight: 27% modified hemp stalk viscose fiber powder, 53% biomass powder, 10% silica fume, and 10% fly ash;
[0066] Everything else is consistent with Example 3.
[0067] Group 2
[0068] The component formulation of the concrete viscosity modifier in Example 3 was replaced with:
[0069] The raw materials include the following percentages by weight: 36% modified hemp stalk viscose fiber powder, 29% biomass powder, 15% silica fume, and 20% fly ash;
[0070] Everything else is consistent with Example 3.
[0071] Group 3
[0072] The concrete viscosity modifier prepared using the component formulation of the concrete viscosity modifier disclosed in Example 3 was added at a dosage of 5% (the mass percentage of the concrete viscosity modifier in the total mixture) while keeping the other component proportions (as shown in Table 1) constant.
[0073] Everything else is consistent with Example 3.
[0074] Group 4
[0075] The concrete viscosity modifier prepared using the component formulation of the concrete viscosity modifier disclosed in Example 3 was added at a dosage of 10% (the mass percentage of the concrete viscosity modifier in the total mixture) while keeping the other component proportions (as shown in Table 1) constant.
[0076] Everything else is consistent with Example 3.
[0077] The test results are shown in Table 3:
[0078] Table 3 Test Data Table
[0079]
[0080] Experimental conclusion: The above experiments show that, compared with Example 3, the concrete viscosity modifier obtained by the formulation of Example 3 has the ability to quickly thicken and increase viscosity in concrete, and also has a good water retention capacity. When the concrete viscosity modifier is used, the effect of rapid thickening and thickening and water retention capacity is the best when its dosage is 7%.
[0081] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.
Claims
1. A concrete viscosity modifier, characterized in that: The raw materials include the following percentages by weight: 27%~45% modified hemp stalk viscose fiber powder, 29%~53% biomass powder, 7%~15% silica fume, and 10%~20% fly ash. The modified hemp stalk viscose fiber powder is obtained by sequentially subjecting hemp stalk viscose fiber to hydrothermal treatment, alkali treatment, drying, and pulverization. The biomass powder is any one or more of oyster shell powder, mussel shell powder, and barnacle powder, and the particle size of the biomass powder is 50-70μm; The preparation method of the biomass powder is as follows: soak the raw materials in a 6%-8% sodium hydroxide solution for 3-5 hours, take out the raw materials and dry them at 40℃-65℃ for 40-48 hours, grind and pulverize them into powder, and dry the powder at 70℃ for 10-12 hours to obtain the biomass powder.
2. The concrete viscosity modifier according to claim 1, characterized in that: The particle size of the modified hemp stalk viscose fiber powder is 40-55 μm.
3. A method for preparing a concrete viscosity modifier as described in any one of claims 1-2, characterized in that: The specific steps are as follows: Step 1: Place hemp stalk viscose fiber in a container and wash it 2-4 times with hot water at 70℃-80℃, each time for 30 minutes. Squeeze out the water and set aside. Step 2: The hemp stalk viscose fiber after the hydrothermal treatment in Step 1 is soaked in an 8%-12% sodium hydroxide solution and heated to 40℃-55℃ for 2-5 hours. Then it is dried at 65℃ for 12 hours for later use. Step 3: The hemp stalk viscose fiber dried in Step 2 is pulverized to obtain modified hemp stalk viscose fiber powder; Step 4: The modified hemp stalk viscose fiber powder obtained in Step 3 is thoroughly mixed with biomass powder and silica fume in an ultrasonic treatment condition according to the mass ratio, and a certain mass ratio of fly ash is added to obtain the concrete viscosity modifier.
4. The method for preparing a concrete viscosity modifier according to claim 3, characterized in that: The ultrasonic treatment involves stirring at 1200-1800 r / min for 8-15 min.
5. A concrete system comprising cementitious materials, aggregates, and water, characterized in that: It also includes the concrete viscosity modifier according to any one of claims 1-2, wherein the amount of the concrete viscosity modifier added is 5%-10%.
6. The concrete system according to claim 5, characterized in that: The mass ratio of cementitious material to water in the concrete system is 1.6-2.3:
1. The cementitious material includes cement, fly ash and slag powder. The cement is PP325 cement. The aggregate includes coarse aggregate and fine aggregate with a gradation ratio of (14-26):(1-1.4).