Microbial interface agent for post-pouring belt, and preparation method and application thereof
By using microbial-induced calcium carbonate deposition technology, which utilizes Bacillus pasteurella to generate calcium carbonate deposits, the problem of water seepage and leakage in post-cast strips has been solved, the density and impermeability of the concrete interface have been improved, and the durability and adhesion of the interface treatment agent have been enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING ZHONGJIAN CONSTR RES INST CO LTD
- Filing Date
- 2024-03-15
- Publication Date
- 2026-05-08
AI Technical Summary
Post-cast strips in cast-in-place concrete structures are prone to water seepage and leakage during construction, becoming a major point of occurrence for building leakage problems, which is difficult to effectively solve with existing technologies.
The microbial-induced calcium carbonate deposition technology utilizes the metabolism of Bacillus pasteurellium to produce urea, which decomposes to generate carbonate ions that combine with metal cations to form gel crystals. Combined with compatibilizers and aliphatic diols, this improves the sealing effect and water resistance of concrete interface treatment agents, and enhances the density and cross-linking strength of the interface between new and old concrete.
It significantly improves the bond strength between new and old concrete interfaces, prevents hollowing and cracking, enhances the anti-seepage performance of the interface treatment, strengthens the density and apparent strength of the interface treatment, prevents hollowing and cracking, improves the durability of the interface treatment agent, enhances the water resistance and durability of the interface treatment agent, and enhances the adhesion of the interface treatment agent.
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Abstract
Description
Technical Field
[0001] This application relates to the technical field of building materials, specifically to a microbial interface agent for post-cast strips, its preparation method, and its application. Background Technology
[0002] Post-cast strips are temporary construction joints installed during the construction of cast-in-place concrete structures to prevent harmful cracking caused by temperature, shrinkage, and settlement. As part of concrete building structures, post-cast strips are an effective measure to address differential settlement and reduce shrinkage stress, and they have corresponding construction standards and requirements. However, in actual construction, due to factors such as construction space and construction techniques, water seepage and leakage through post-cast strips occur frequently, making it one of the main points of occurrence and common problems in building leakage.
[0003] To address the aforementioned issues, it is crucial to develop a post-cast strip (interface between new and old concrete) treatment process that is easy to construct and has excellent anti-leakage performance. Summary of the Invention
[0004] To address the aforementioned technical problems, this application provides a microbial interface agent for post-cast strips, its preparation method, and its application.
[0005] In a first aspect, this application provides a microbial interface agent for post-cast strips, specifically comprising the following components in parts by weight: 0.02-0.06 parts of Bacillus pasteurellium bacterial solution, 90-110 parts of cement slurry with a water-cement ratio of 0.4-0.5, 0.5-1 part of foaming agent, 0.1-0.5 parts of compatibilizer, 0.2-0.5 parts of calcium salt saturated solution, and 0.03-0.07 parts of aliphatic diol;
[0006] The compatibilizer is selected from one or more of sodium dodecyl sulfate, cocamide, and polyoxyethylene ether;
[0007] The calcium salt saturated solution is selected from one or more of calcium acetate solution, calcium formate solution, and calcium hypophosphite solution.
[0008] This application is based on microbial induced calcium carbonate deposition technology (MICP technology), which utilizes Bacillus pasteurellii in nature. Its metabolism can produce urease that decomposes urea. The carbonate ions produced after the decomposition of urea combine with free metal cations in nature to form gel crystals, which can then seal the base surface of new and old concrete, giving it excellent sealing properties. This can improve the density and apparent strength of the base layer, prevent hollowing and cracking, and improve the anti-leakage performance.
[0009] The addition of compatibilizers and aliphatic diols is mainly used to improve the sealing effect and water resistance of concrete interface treatment agents, and to improve the density and apparent strength of concrete interface treatment agents and cement after mixing and roughening. At the same time, it can improve the crosslinking density and crosslinking strength between concrete interface treatment agents and old concrete substrates, significantly improving the water resistance and durability of concrete interface treatment agents and significantly increasing their adhesion to the substrate.
[0010] Preferably, the microbial interface agent specifically comprises the following components in parts by weight: 0.03-0.05 parts of Bacillus pasteurellium bacterial culture, 96-104 parts of cement slurry with a water-cement ratio of 0.4-0.5, 0.7-0.9 parts of foaming agent, 0.2-0.4 parts of compatibilizer, 0.3-0.4 parts of calcium salt saturated solution, and 0.04-0.06 parts of aliphatic diol.
[0011] Preferably, the compatibilizer is composed of sodium dodecyl sulfate and cocoamide in a weight ratio of 3-5:3-5.
[0012] In one specific implementation, the weight ratio of sodium dodecyl sulfate and cocoamide in the compatibilizer can be 3:3, 3:4, 3:5, 4:3, 4:4, 4:5, 5:3, 5:4, or 5:5.
[0013] In some specific implementations, the weight ratio of sodium dodecyl sulfate and cocoamide in the compatibilizer can be 3-4:3, 3-5:4, 3-4:5, 4:3-4, 4:4-5, 4:3-5, 3-5:3, 4-5:4, or 5:3-5.
[0014] Experimental analysis shows that the use of sodium dodecyl sulfate and cocoamide in the above weight ratio as compatibilizers in this application can further improve the performance of microbial interface agents in post-cast strips.
[0015] Preferably, in the compatibilizer, the amount of sodium dodecyl sulfate is greater than the amount of cocoamide.
[0016] Preferably, the aliphatic diol is one or more selected from ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, neopentyl glycol, 2-methyl-1,3-propanediol, diethylene glycol, 1,4-cyclohexanediol, and 1,4-cyclohexanediethanol.
[0017] Preferably, the aliphatic diol is composed of a mixture of 1,2-butanediol and diethylene glycol in a weight ratio of 10:1-2.
[0018] In one specific embodiment, the weight ratio of 1,2-butanediol to diethylene glycol in the aliphatic diol can be 10:1, 10:1.5, or 10:2.
[0019] In some specific embodiments, the weight ratio of 1,2-butanediol and diethylene glycol in the aliphatic diol can also be 10:1-1.5 or 10:1.5-2.
[0020] Experimental analysis shows that the selection of 1,2-butanediol and diethylene glycol in the above weight ratio as aliphatic diols for preparing microbial interface agents can further improve the application performance of microbial interface agents in post-cast strips.
[0021] Preferably, the foaming agent comprises the following components in parts by weight: 1.0-1.4 parts sodium chloride, 1.2-1.7 parts sodium thiosulfate, 0.2-0.4 parts stretching powder BX, 0.3-0.5 parts water-reducing agent JN, 0.6-0.10 parts ammonium chloride, 0.003-0.007 parts aluminum powder, and 0.003-0.007 parts iron powder.
[0022] Secondly, this application provides a method for preparing the above-mentioned microbial interface agent, specifically including the following steps:
[0023] Add foaming agent and one-sixth to one-half of compatibilizer to the cement slurry with a water-cement ratio of 0.4-0.5, and stir evenly to obtain slurry;
[0024] Mix the saturated calcium salt solution, the remaining amount of compatibilizer, and the aliphatic diol thoroughly to obtain a premixed solution;
[0025] Add the Bacillus pasteurellium bacterial solution to the slurry and continue mixing until homogeneous; then add the premixed solution and mix until homogeneous to obtain the microbial interface agent.
[0026] In the preparation method of microbial interface agents, the order of adding raw materials has a significant impact on the application of microbial interface agents in the field of concrete. The applicant found that when the above technical solution is adopted, the microbial interface agent can significantly improve the impermeability of concrete.
[0027] Thirdly, this application provides the application of the above-mentioned microbial interface agent in post-pouring strips and the interface between new and old concrete.
[0028] Fourthly, this application provides a process for treating the interface between new and old concrete, specifically including the following steps:
[0029] Roughen and clean the post-cast strip area of the old concrete interface, and thoroughly wet it;
[0030] Spray the above-mentioned microbial interface agent onto the old concrete interface to a thickness of 3-5 mm, and then spray with an 820-880 mg / L urea solution.
[0031] Pour new concrete 4-6 minutes later, and vibrate it thoroughly. Then cure it according to the construction standards.
[0032] In summary, the technical solution of this application has the following effects:
[0033] This application is based on microbial induced calcium carbonate deposition technology, which utilizes Bacillus pasteurellii in nature. Its metabolism can produce urease that decomposes urea. The carbonate ions produced after urea decomposition combine with free metal cations in nature to form gel crystals, which can then seal the base surface of new and old concrete, giving it excellent sealing properties. This can improve the density and apparent strength of the base layer, prevent hollowing and cracking, and improve the anti-leakage performance.
[0034] The compatibilizer and aliphatic diol in the technical solution provided in this application are mainly used to improve the sealing effect and water resistance of the concrete interface treatment agent, and to improve the density and apparent strength of the concrete interface treatment agent and cement after mixing and roughening; at the same time, they can improve the crosslinking density and crosslinking strength between the concrete interface treatment agent and the old concrete substrate, so that the water resistance and durability of the concrete interface treatment agent are significantly improved, and the adhesion to the substrate is significantly increased. Detailed Implementation
[0035] The present application will be further described in detail below with reference to embodiments, comparative examples and performance test results. These embodiments should not be construed as limiting the scope of protection claimed in this application.
[0036] Example
[0037] Examples 1-3
[0038] Examples 1-3 provide a microbial interface agent for post-cast strips.
[0039] The difference in the above embodiments is that the amount of each raw material component is different, as shown in Table 1.
[0040] The specific preparation method of the microbial interface agent in the above embodiments is as follows:
[0041] Pasteurella multocida bacterial solution:
[0042] Preparation of foaming agent: Sodium chloride 1.2g, sodium thiosulfate 1.5g, foaming powder BX 0.3g, water reducing agent JN 0.4g, ammonium chloride 0.08g, aluminum powder 0.005g, iron powder 0.005g, mix to obtain the foaming agent.
[0043] Compatibilizer: Composed of sodium dodecyl sulfate and cocoamide in a weight ratio of 5:3.
[0044] Saturated calcium salt solution: calcium hypophosphate solution.
[0045] Aliphatic diols: Composed of a mixture of 1,2-butanediol and diethylene glycol in a weight ratio of 10:1.5.
[0046] Prepare a cement slurry with a water-cement ratio of 0.45, then add a foaming agent and one-third of the amount of compatibilizer, and stir evenly to obtain the slurry.
[0047] Mix the saturated calcium salt solution, the remaining amount of compatibilizer, and the aliphatic diol thoroughly to obtain a premixed solution;
[0048] Add Pasteurella multocida bacterial solution to the slurry and continue mixing until homogeneous; then add premixed solution and mix until homogeneous to obtain microbial interface agent.
[0049] Table 1. Dosage of each raw material component in the microbial interface agent in Examples 1-3 and Comparative Examples 1-2
[0050]
[0051] Examples 4-8
[0052] Examples 4-8 each provide a microbial interface agent for post-cast strips.
[0053] The difference between the above embodiment and Embodiment 2 is that the composition of the compatibilizer is different, as shown below.
[0054] In Example 4: the compatibilizer is sodium dodecyl sulfate.
[0055] In Example 5: The compatibilizer is composed of sodium dodecyl sulfate and polyoxyethylene ether in a weight ratio of 5:3.
[0056] In Example 6: The compatibilizer is composed of sodium dodecyl sulfate and cocoamide in a weight ratio of 3:5.
[0057] In Example 7: The compatibilizer is composed of sodium dodecyl sulfate and cocoamide in a weight ratio of 4:4.
[0058] In Example 8: The compatibilizer is composed of sodium dodecyl sulfate and cocoamide in a weight ratio of 4:3.
[0059] The types of other raw material components, the amounts of each raw material component, and the preparation method of the microbial interface agent are the same in the above embodiments and in Example 2.
[0060] Examples 9-13
[0061] Examples 9-13 provide a microbial interface agent for post-cast strips.
[0062] The difference between the above embodiments and Embodiment 2 is that the types of aliphatic diols are different, as shown below.
[0063] In Example 9: the aliphatic diol is 1,2-butanediol.
[0064] In Example 10: the aliphatic diol is composed of a mixture of ethylene glycol and diethylene glycol in a weight ratio of 10:1.5.
[0065] In Example 11: the aliphatic diol was composed of a mixture of 1,2-butanediol and diethylene glycol in a weight ratio of 10:0.5.
[0066] In Example 12: the aliphatic diol was composed of a mixture of 1,2-butanediol and diethylene glycol in a weight ratio of 10:1.
[0067] In Example 13: the aliphatic diol was composed of a mixture of 1,2-butanediol and diethylene glycol in a weight ratio of 10:2.
[0068] The types of other raw material components, the amounts of each raw material component, and the preparation method of the microbial interface agent are the same in the above embodiments and in Example 2.
[0069] Comparative Example
[0070] Comparative Examples 1-2
[0071] Comparative Examples 1 and 2 each provide a microbial interface agent for post-cast strips.
[0072] The difference between the above comparative examples lies in the amount of each raw material component used, as shown in Table 1.
[0073] The types of raw material components, the amounts of each raw material component, and the preparation method of the microbial interface agent in the above comparative example and Example 2 are all the same.
[0074] Comparative Examples 3-4
[0075] Comparative Examples 3 and 4 each provide a microbial interface agent for post-cast strips.
[0076] The difference in the above comparative examples lies in the amount of each raw material component used, as shown below.
[0077] In Comparative Example 3: the compatibilizer was vinyltrimethoxysilane.
[0078] In Comparative Example 4, an equal amount of glycerol was used instead of an aliphatic diol.
[0079] The types of raw material components, the amounts of each raw material component, and the preparation method of the microbial interface agent in the above comparative example and Example 2 are all the same.
[0080] Performance testing
[0081] Prepare standard-sized C30 P8 impermeable concrete specimens according to the standard mix proportion at 20±5℃ and ≥95% humidity. After demolding, cure for 28 days in a standard curing environment at 20±2℃ and ≥95% humidity (the specimens should be prepared in the same batch and on the same day).
[0082] After placing φ18HRB400E steel bars in the center of the specimen, the specimen was pressed under a concrete press until the concrete specimen cracked from the center, which was then used as old concrete.
[0083] Roughen and clean the post-cast strip area of the old concrete interface, and thoroughly wet it;
[0084] Spray the microbial interface agent prepared in the examples or comparative examples onto the old concrete interface to a thickness of 3-5 mm, and then spray with an 846 mg / L urea solution.
[0085] Pour new concrete 4-6 minutes later and vibrate it thoroughly. Note that the vibrator should not come into close contact with the solvent-coated area. After pouring, cure normally according to the construction standards.
[0086] Then, the following properties of the concrete after 28 days of curing were tested.
[0087] (1) According to the testing standard JC / T907-2002 Concrete Interface Treatment Agent, the physical properties of shear bond strength and tensile bond strength of the concrete prepared in Examples 1-13 and Comparative Examples 1-4 were tested.
[0088] After curing, the concrete was immersed in water for 24 hours, and the physical properties of shear bond strength and tensile bond strength were tested to evaluate the durability of the concrete.
[0089] The test results are shown in Table 2.
[0090] (2) According to the test method specified in GB / T 50082-2009, start the permeability tester, open the valves under the 24 test positions, so that water seeps out from the 24 holes and fills the test position pit, then close the permeability tester and install the sealed test specimen on the permeability tester.
[0091] During the test, the water pressure started at 0.1 MPa and increased by 0.01 MPa every hour. The condition of the specimen end face was observed at all times, and the water discharge from the specimen end face and the corresponding pressure were recorded to test the concrete's impermeability.
[0092] Table 2 Performance test results of the microbial interface agents in Examples 1-13 and Comparative Examples 1-4
[0093]
[0094] Based on Table 2, and by comparing the test results of Examples 1-13 and Comparative Examples 1-4, this application utilizes one or more of sodium dodecyl sulfate, cocoamide, and polyoxyethylene ether as compatibilizers, and one or more of calcium acetate solution, calcium formate solution, and calcium hypophosphite solution as calcium salt saturated solutions, in combination with Bacillus pasteurization liquid, cement slurry, foaming agent, and aliphatic diol in specific weight proportions to prepare a microbial interface agent. This agent is then applied to the treatment process of the interface between new and old concrete in post-cast strips, which can significantly improve the compactness and apparent strength of the base layer, thereby effectively increasing the bond strength between the new and old concrete interfaces while ensuring its impermeability.
[0095] By comparing the test results of Examples 1-3 and Comparative Examples 1-2, it was found that the amount of each component raw material in the microbial interface agent has a significant impact on the application performance of the microbial interface agent. This application has determined the amount of each component through multiple experiments, thereby significantly improving the performance of the prepared microbial interface agent.
[0096] By comparing the test results of Examples 2, 4-8 and Comparative Example 3, it was found that the microbial interface agent prepared by Comparative Example 3 using vinyltrimethoxysilane as a compatibilizer had poor application performance. In contrast, this application uses one or more of sodium dodecyl sulfate, cocamide, and polyoxyethylene ether as compatibilizers, which can significantly improve the performance of the microbial interface agent; furthermore, this application uses a mixture of sodium dodecyl sulfate and cocamide in a weight ratio of 3-5:3-5 as a compatibilizer.
[0097] By comparing the test results of Examples 2, 9-13 and Comparative Example 4, it can be seen that compared with the use of glycerol, the use of aliphatic diols in this application to prepare microbial interface agents can significantly improve the performance of concrete. Furthermore, the use of a mixture of 1,2-butanediol and diethylene glycol in a weight ratio of 10:1-2 as aliphatic diols can further improve the application performance of microbial interface agents.
[0098] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.
Claims
1. A microbial interface agent for post-cast strips, characterized in that, Specifically, it includes the following components in parts by weight: 0.02-0.06 parts of Bacillus pasteurization solution, 90-110 parts of cement slurry with a water-cement ratio of 0.4-0.5, 0.5-1 part of foaming agent, 0.1-0.5 parts of compatibilizer, 0.2-0.5 parts of calcium salt saturated solution, and 0.03-0.07 parts of aliphatic diol; The compatibilizer is selected from one or more of sodium dodecyl sulfate, cocamide, and polyoxyethylene ether; The calcium salt saturated solution is selected from one or more of calcium acetate solution, calcium formate solution, and calcium hypophosphite solution.
2. The microbial interface agent according to claim 1, characterized in that, Specifically, it includes the following components in parts by weight: 0.03-0.05 parts of Bacillus pasteurization solution, 96-104 parts of cement slurry with a water-cement ratio of 0.4-0.5, 0.7-0.9 parts of foaming agent, 0.2-0.4 parts of compatibilizer, 0.3-0.4 parts of calcium salt saturated solution, and 0.04-0.06 parts of aliphatic diol.
3. The microbial interface agent according to claim 1, characterized in that, The compatibilizer is composed of sodium dodecyl sulfate and cocoamide in a weight ratio of 3-5:3-5.
4. The microbial interface agent according to claim 3, characterized in that, In the compatibilizer, the amount of sodium dodecyl sulfate is greater than the amount of cocoamide.
5. The microbial interface agent according to claim 1, characterized in that, The aliphatic diol is one or more of ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, neopentyl glycol, 2-methyl-1,3-propanediol, diethylene glycol, 1,4-cyclohexanediol, and 1,4-cyclohexanediol.
6. The microbial interface agent according to claim 5, characterized in that, The aliphatic diol is composed of a mixture of 1,2-butanediol and diethylene glycol in a weight ratio of 10:1-2.
7. The microbial interface agent according to claim 1, characterized in that, The foaming agent comprises the following components in parts by weight: 1.0-1.4 parts sodium chloride, 1.2-1.7 parts sodium thiosulfate, 0.2-0.4 parts stretching powder BX, 0.3-0.5 parts water-reducing agent JN, 0.6-0.10 parts ammonium chloride, 0.003-0.007 parts aluminum powder, and 0.003-0.007 parts iron powder.
8. The method for preparing the microbial interface agent according to any one of claims 1-7, characterized in that, Specifically, the following steps are included: Add foaming agent and one-sixth to one-half of compatibilizer to the cement slurry with a water-cement ratio of 0.4-0.5, and stir evenly to obtain slurry; Mix the saturated calcium salt solution, the remaining amount of compatibilizer, and the aliphatic diol thoroughly to obtain a premixed solution; Add the Bacillus pasteurellium bacterial solution to the slurry and continue mixing until homogeneous; then add the premixed solution and mix until homogeneous to obtain the microbial interface agent.
9. The application of the microbial interface agent according to any one of claims 1-7 in post-cast strips and the interface between new and old concrete.
10. A process for treating the interface between new and old concrete, characterized in that, Specifically, the following steps are included: Roughen and clean the post-cast strip area of the old concrete interface, and thoroughly wet it; Spray the microbial interface agent according to any one of claims 1-7 onto the old concrete interface, with a thickness of 3-5 mm, and then spray with an 820-880 mg / L urea solution. Pour new concrete 4-6 minutes later, and vibrate it thoroughly. Then cure it according to the construction standards.
Citation Information
Patent Citations
Microbial self-repairing concrete and preparation method thereof
CN112500074A
Waterproof galling concrete interface treating agent and construction method thereof
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