Low-carbon cement-based microbial concrete and preparation method thereof
Through the ratio of low-carbon cement-based microbial concrete and the use of microbial solutions, the problems of high energy consumption and carbon dioxide emissions of silicate cement are solved, the early strength of supersulfate cement is improved and the self-repair ability of concrete is realized.
Patent Information
- Application Number
- CN202411202739.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2024-12-10
AI Technical Summary
The existing silicate cement emits a large amount of carbon dioxide during the preparation process, has high resource consumption, and the early strength of supersulfate cement is low, which has potential harm to construction applications.
Using low-carbohydrate cement-based microbial concrete ratio, including ultrasulfate cement, fly ash, microbial solutions, sand, stone, water reducing agent, gas induction agent, calcium lactate and urea, it is formed by stirring and vibrating, and added Mineralization of microbial strains to improve early intensity and self-healing ability.
It has achieved energy reuse, low energy consumption, low CO2 emissions, early strength improvement and self-repair of concrete, solving the problem of insufficient strength of ultrasulfate cement in the early stage.
Smart Images
Figure CN119100729A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of microbial concrete proportioning, in particular to low-carbon cement-based microbial concrete and a preparation method thereof. Background Art
[0002] Ordinary Portland cement emits a large amount of carbon dioxide during its preparation process and its raw materials are non-renewable energy, which consumes a lot of resources. In comparison, super-sulfated cement, which has low carbon dioxide emissions and whose raw materials are mostly industrial waste, is more environmentally friendly. However, as research on super-sulfated cement has found, its early strength is low, and it may be harmful if used directly in construction.
[0003] Therefore, there is an urgent need to provide a low-carbon cement-based microbial concrete and a preparation method thereof to solve the above problems. Summary of the invention
[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a low-carbon cement-based microbial concrete and a preparation method thereof to solve the problems raised in the background technology.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a low-carbon cement-based microbial concrete, in which the mass proportion of each component is: 280 parts of supersulfate cement, 70 parts of grade II fly ash, 166.4 parts of microbial solution, 752 parts of sand, 1145 parts of stone, 2.1 parts of water reducer, 0.158 parts of air entraining agent, 4.2 parts of calcium lactate and 1.16 parts of urea.
[0006] Preferably, the mass proportions of the components of the supersulfate cement are: 75-85 parts of blast furnace slag, 10-20 parts of phosphogypsum and 1-5 parts of cement clinker.
[0007] Preferably, the blast furnace slag has a 7d activity index of 90%, a 28d activity index of 99%, and a specific surface area of 589 m 2 / kg.
[0008] Preferably, the mass content of the phosphogypsum hemihydrate is 67.4%, and the specific surface area is 852m 2 / kg.
[0009] Preferably, the cement clinker is P.O42.5 ordinary Portland cement with a specific surface area of 420m 2 / kg.
[0010] Preferably, the sand material is natural river valley sand with a fineness modulus of 2.75 and an average particle size of 0.5-0.25 mm.
[0011] Preferably, the stone grading is a two-stage grading, including small stones with a particle size range of 5 to 20 mm and medium stones with a particle size range of 20 to 40 mm.
[0012] Preferably, the microorganisms in the microbial solution are selected from species that can undergo mineralization and deposition reactions.
[0013] In addition, the present invention also discloses a method for preparing low-carbon cement-based microbial concrete, which comprises the following steps: Step 1: Put blast furnace slag, phosphogypsum and cement clinker into a mixer according to the proportion of components and mix them evenly to prepare super sulfate cement; Step 2: Prepare microbial solution; Step 3: Weigh the raw materials according to the proportion, use a forced mixer to mix the super sulfate cement, grade II fly ash, sand, stone, calcium lactate and urea according to the proportion; Step 4: Add microbial solution, air entraining agent and water reducing agent according to the proportion for the second mixing; Step 5: Put the obtained mixture into the mold which has been brushed with release agent in advance, and then put the mold on the vibration table and vibrate for 30 seconds; Step 6: After the specimen is formed, place it in a room with a room temperature of 20±5℃, cover the surface of the mold with a plastic film and sprinkle water on it, and demold it after standing for 48 hours; Step 7: Finally, place the specimen in a room at a temperature of 20±2℃ and immerse it in water for 28 days. The preparation is complete.
[0014] Furthermore, the specific method steps for preparing the microbial solution in Step 2 are: Step 2.1, mix soybean, casein peptone, sodium chloride, urea and ultrapure water in a mass ratio of 1:3:1:4:200 to prepare a liquid culture medium; Step 2.2, sterilize at 121°C for 15 minutes in an autoclave, then place in a clean bench and irradiate with ultraviolet light for 15 minutes. When the temperature drops to room temperature, add NaOH solution to the culture medium to adjust the pH to 11; Step 2.3, scrape the microorganisms on the solid culture medium with an inoculation loop and put them into the liquid culture medium, seal the conical flask after inoculation with gauze, and then put it into a constant temperature shaking box for 48 hours, set the temperature to 30℃ and the speed to 120r / min; Step 2.4, after the shaking is completed, the microbial solution is placed in a centrifuge with a speed of 4500r / min and centrifuged for 10 minutes. After the centrifugation is completed, the microbial solution is rinsed out of the centrifuge tube with ultrapure water and the concentration of the microbial solution is set to 10 6 ~10 8 cells / ml.
[0015] The present invention has the following beneficial effects: 1. The raw materials for preparing the supersulfated cement in the present invention are slag, phosphogypsum, etc., which can realize the reuse of energy. The preparation process only requires stirring, and the energy consumption and CO2 emission are small. The amount of clinker in the raw materials is small, which reduces a large amount of hydration heat and effectively controls the generation of temperature cracks. 2. After adding the microbial solution in the present invention, the early strength of the concrete is significantly improved, improving the defect of low early strength of supersulfate cement concrete; 3. After the concrete cracks, the microbial strains mixed in the present invention can also undergo mineralization and deposition reactions to achieve self-repair of the concrete cracks. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a flow chart of the preparation method of the present invention; Figure 2 This is a data comparison chart of the embodiments of the present invention. DETAILED DESCRIPTION
[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: See also Figure 1 to Figure 2 A low-carbon cement-based microbial concrete, the weight of each component is: 280 parts of supersulfate cement, 70 parts of grade II fly ash, 166.4 parts of microbial solution, 752 parts of sand, 1145 parts of stone, 2.1 parts of water reducer, 0.158 parts of air entraining agent, 4.2 parts of calcium lactate and 1.16 parts of urea. The water reducer is a polycarboxylic acid water reducer, and the air entraining agent is an Air202 air entraining agent.
[0018] Preferably, the mass proportions of the components of the supersulfate cement are: 75-85 parts of blast furnace slag, 10-20 parts of phosphogypsum and 1-5 parts of cement clinker.
[0019] Preferably, the blast furnace slag has a 7d activity index of 90%, a 28d activity index of 99%, and a specific surface area of 589 m2 / kg.
[0020] Preferably, the mass content of the phosphogypsum hemihydrate is 67.4%, and the specific surface area is 852m 2 / kg.
[0021] Preferably, the cement clinker is P.O42.5 ordinary Portland cement with a specific surface area of 420m 2 / kg.
[0022] Preferably, the sand material is natural river valley sand with a fineness modulus of 2.75 and an average particle size of 0.5-0.25 mm.
[0023] Preferably, the stone grading is a two-stage grading, including small stones with a particle size range of 5 to 20 mm and medium stones with a particle size range of 20 to 40 mm. Before use, the impurities on the surface of the stone need to be cleaned and dried to prevent excessive bacteria from affecting the performance of the concrete.
[0024] Preferably, the microorganisms in the microbial solution are selected from species that can undergo mineralization and deposition reactions. In the present invention, Bacillus pasteurianus can be used.
[0025] In addition, the present invention also discloses a method for preparing low-carbon cement-based microbial concrete, which comprises the following steps: Step 1: Put blast furnace slag, phosphogypsum and cement clinker into a mixer according to the proportion of components and mix them evenly to prepare super sulfate cement; Step 2: Prepare microbial solution; Step 3: Weigh the raw materials according to the proportion, use a forced mixer to mix the super sulfate cement, grade II fly ash, sand, stone, calcium lactate and urea according to the proportion; Step 4: Add microbial solution, air entraining agent and water reducing agent according to the proportion for the second mixing; Step 5: Put the obtained mixture into the mold which has been brushed with release agent in advance, and then put the mold on the vibration table and vibrate for 30 seconds; Step 6: After the specimen is formed, place it in a room with a room temperature of 20±5℃, cover the surface of the mold with a plastic film and sprinkle water on it, and demold it after standing for 48 hours; Step 7: Finally, place the specimen in a room at a temperature of 20±2℃ and immerse it in water for 28 days. The preparation is complete.
[0026] Furthermore, the specific method steps for preparing the microbial solution in Step 2 are: Step 2.1, mix soybean, casein peptone, sodium chloride, urea and ultrapure water in a mass ratio of 1:3:1:4:200 to prepare a liquid culture medium; Step 2.2, sterilize at 121°C for 15 minutes in an autoclave, then place in a clean bench and irradiate with ultraviolet light for 15 minutes. When the temperature drops to room temperature, add NaOH solution to the culture medium to adjust the pH to 11; Step 2.3, scrape the microorganisms on the solid culture medium with an inoculation loop and put them into the liquid culture medium, seal the conical flask after inoculation with gauze, and then put it into a constant temperature shaking box for 48 hours, set the temperature to 30℃ and the speed to 120r / min; Step 2.4, after the shaking is completed, the microbial solution is placed in a centrifuge with a speed of 4500r / min and centrifuged for 10 minutes. After the centrifugation is completed, the microbial solution is rinsed out of the centrifuge tube with ultrapure water and the concentration of the microbial solution is set to 10 6 ~10 8 cells / ml.
[0027] Example 1 A low-carbon cement-based microbial concrete, the components of which include: 280 parts of supersulfated cement, 70 parts of grade II fly ash, 166.4 parts of microbial solution, 752 parts of sand, 1145 parts of stone, 2.1 parts of water reducer, 0.158 parts of air entraining agent, 4.2 parts of calcium lactate and 1.16 parts of urea; wherein the components of the supersulfated cement include: 75 parts of blast furnace slag, 20 parts of phosphogypsum and 5 parts of cement clinker, and the concentration of the microbial solution is 10 6 cells / ml.
[0028] Example 2 A low-carbon cement-based microbial concrete, the components of which include: 280 parts of supersulfated cement, 70 parts of grade II fly ash, 166.4 parts of microbial solution, 752 parts of sand, 1145 parts of stone, 2.1 parts of water reducer, 0.158 parts of air entraining agent, 4.2 parts of calcium lactate and 1.16 parts of urea; wherein the components of the supersulfated cement include: 75 parts of blast furnace slag, 20 parts of phosphogypsum and 5 parts of cement clinker, and the concentration of the microbial solution is 10 7 cells / ml.
[0029] Example 3 A low-carbon cement-based concrete, wherein the proportions of the components include: 280 parts of supersulfated cement, 70 parts of grade II fly ash, 166.4 parts of microbial solution, 752 parts of sand, 1145 parts of stone, 2.1 parts of water reducer, 0.158 parts of air entraining agent, 4.2 parts of calcium lactate and 1.16 parts of urea; wherein the proportions of the components of the supersulfated cement include: 75 parts of blast furnace slag, 20 parts of phosphogypsum and 5 parts of cement clinker, and the concentration of the microbial solution is 10 8 cells / ml.
[0030] Comparative Example 1 A low-carbon cement-based concrete, wherein the proportion of each component includes: 280 parts of supersulfated cement, 70 parts of grade II fly ash, 166.4 parts of ultrapure water, 752 parts of sand, 1145 parts of stone, 2.1 parts of water reducer, 0.158 parts of air entraining agent, 4.2 parts of calcium lactate and 1.16 parts of urea; wherein the proportion of each component of the supersulfated cement includes: 75 parts of blast furnace slag, 20 parts of phosphogypsum and 5 parts of cement clinker.
[0031] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.
Claims
1. A low-carbon cement-based microbial concrete, Features: The mass proportion of each component is: 280 parts of super sulfate cement, 70 parts of grade II fly ash, 166.4 parts of microbial solution, 752 parts of sand, 1145 parts of stone, 2.1 parts of water reducer, 0.158 parts of air entraining agent, 4.2 parts of calcium lactate and 1.16 parts of urea.
2. A low-carbon cement-based microbial concrete according to claim 1, Features: The weight proportions of the components of the supersulfate cement are: 75-85 parts of blast furnace slag, 10-20 parts of phosphogypsum and 1-5 parts of cement clinker.
3. A low-carbon cement-based microbial concrete according to claim 2, Features: The blast furnace slag has a 7d activity index of 90%, a 28d activity index of 99%, and a specific surface area of 589m 2 / kg.
4. A low-carbon cement-based microbial concrete according to claim 2, Features: The mass content of the phosphogypsum hemihydrate is 67.4%, and the specific surface area is 852m 2 / kg.
5. A low-carbon cement-based microbial concrete according to claim 2, Features: The cement clinker is P.O42.5 ordinary Portland cement with a specific surface area of 420m 2 / kg.
6. The low-carbon cement-based microbial concrete according to claim 1, Features: The sand material is natural sand from the river valley, with a fineness modulus of 2.75 and an average particle size of 0.5-0.25 mm.
7. The low-carbon cement-based microbial concrete according to claim 1, Features: The stone grading is a two-level grading, including small stones with a particle size range of 5 to 20 mm and medium stones with a particle size range of 20 to 40 mm.
8. The low-carbon cement-based microbial concrete according to claim 1, Features: The microorganisms in the microbial solution are selected from strains that can carry out mineralization and deposition reactions.
9. A method for preparing a low-carbon cement-based microbial concrete according to any one of claims 1 to 8, Features: It includes the following steps: Step 1: Put blast furnace slag, phosphogypsum and cement clinker into a mixer according to the proportion of components and mix them evenly to prepare super sulfate cement; Step 2: Prepare microbial solution; Step 3: Weigh the raw materials according to the proportion, use a forced mixer to mix the super sulfate cement, grade II fly ash, sand, stone, calcium lactate and urea according to the proportion; Step 4: Add microbial solution, air entraining agent and water reducing agent according to the proportion for the second mixing; Step 5: Put the obtained mixture into the mold which has been brushed with release agent in advance, and then put the mold on the vibration table and vibrate for 30 seconds; Step 6: After the specimen is formed, place it in a room with a room temperature of 20±5℃, cover the surface of the mold with a plastic film and sprinkle water on it, and demold it after standing for 48 hours; Step 7: Finally, place the specimen in a room at a temperature of 20±2℃ and immerse it in water for 28 days. The preparation is complete.
10. The method for preparing a low-carbon cement-based microbial concrete according to claim 9, Features: The specific method steps for preparing the microbial solution in Step 2 are: Step 2.1, mix soybean, casein peptone, sodium chloride, urea and ultrapure water in a mass ratio of 1:3:1:4:200 to prepare a liquid culture medium; Step 2.2, sterilize at 121°C for 15 minutes in an autoclave, then place in a clean bench and irradiate with ultraviolet light for 15 minutes. When the temperature drops to room temperature, add NaOH solution to the culture medium to adjust the pH to 11; Step 2.3, scrape the microorganisms on the solid culture medium with an inoculation loop and put them into the liquid culture medium, seal the conical flask after inoculation with gauze, and then put it into a constant temperature shaking box for 48 hours, set the temperature to 30℃ and the speed to 120r / min; Step 2.4, after the shaking is completed, the microbial solution is placed in a centrifuge with a speed of 4500r / min and centrifuged for 10 minutes. After the centrifugation is completed, the microbial solution is rinsed out of the centrifuge tube with ultrapure water and the concentration of the microbial solution is set to 10 6 ~10 8 cells / ml.