阅读说明：本技术 一种混凝土裂缝生物修复方法 (Concrete crack biological repairing method ) 是由 加尼·阿卜杜勒·瑞泽普 赵婷 于 2020-04-13 设计创作，主要内容包括：本发明提供了一种混凝土裂缝生物修复方法,该方法通过将巴氏芽孢杆菌溶液、尿素溶液和可溶性钙盐溶液依次注入混凝土裂缝中,多余的液体从混凝土裂缝中渗出停止操作,1小时后,重复操作,从而修复混凝土裂缝。该方法利用巴氏芽孢杆菌分解尿素,然后再钙源存在的情况下,生成碳酸钙沉淀,从而修复混凝土裂缝。本发明以细菌、尿素和可溶性钙盐为产生碳酸钙的原料,廉价易得。本发明细菌修复过程简单易操作,而且产生碳酸钙的过程为生物过程,环境友好。(The invention provides a concrete crack bioremediation method, which comprises the steps of sequentially injecting a bacillus pasteurianus solution, a urea solution and a soluble calcium salt solution into a concrete crack, enabling redundant liquid to seep out of the concrete crack to stop operation, and repeating the operation after 1 hour, thereby repairing the concrete crack. According to the method, the bacillus pasteurii is used for decomposing urea, and then calcium carbonate precipitates are generated under the condition that a calcium source exists, so that concrete cracks are repaired. The invention takes bacteria, urea and soluble calcium salt as raw materials for producing calcium carbonate, and is cheap and easy to obtain. The bacterial remediation process is simple and easy to operate, and the process of producing calcium carbonate is a biological process and is environment-friendly.)

1. A concrete crack bioremediation method is characterized in that: according to the method, a bacillus pasteurianus solution, a urea solution and a soluble calcium salt solution are sequentially injected into a concrete crack, redundant liquid seeps out of the concrete crack to stop operation, and the operation is repeated after 1 hour, so that the concrete crack is repaired.

2. The concrete crack bioremediation method of claim 1, wherein: the concentration of the soluble calcium salt solution is 1-2 mol/L.

3. The concrete crack bioremediation method of claim 1, wherein: the concentration of the urea solution is 1-2 mol/L.

4. The concrete crack bioremediation method of claim 1, wherein: the concentration of the Pasteurella solution is 1.2 multiplied by 10⁸cell·mL^-1。

5. The concrete crack bioremediation method of claim 1, wherein: the injection volumes of the pasteuria bacillus solution, the urea solution and the soluble calcium salt solution are the same.

6. The concrete crack bioremediation method of claim 1, wherein: the soluble calcium salt solution is Ca (NO)₃)₂Solution, calcium chloride solution or calcium acetate solution.

7. The concrete crack bioremediation method of claim 1, wherein: the culture temperature of the pasteurella bacillus solution is 10-40 ℃, and the culture time is 15-18 hours.

8. The concrete crack bioremediation method of claim 1, wherein: the culture temperature of the pasteuria bacillus solution is 20 ℃.

Technical Field

The invention belongs to the technical field of concrete crack repair, and particularly relates to a method for repairing concrete cracks by decomposing urea and inducing calcium carbonate precipitation through bacillus pasteurii.

Background

Concrete is one of the most important building materials in the world. However, the tensile strength of concrete is low, and cracks are inevitably generated. After concrete cracks appear, many harmful substances such as acid, alkali, gas and water invade the interior of the concrete portion through a single mechanism or a combined mechanism such as diffusion, capillary action, permeation, etc., resulting in corrosion of steel bars and deterioration of concrete structures. If other harmful substances reach the inside of the concrete, they may react with the components of the concrete or directly damage the structure of the concrete, thereby seriously affecting the durability of the concrete. Therefore, how to effectively repair the concrete cracks is very important.

Although the existing traditional concrete crack repairing methods such as epoxy resin injection, gravity filling, polymer impregnation and the like have good engineering effects, the used materials such as epoxy resin, carbamate and the like are easy to age, have low heat resistance and different thermal expansion coefficients with concrete, and the repaired concrete crack may be secondarily cracked, which is not acceptable for economic and safety reasons.

Aiming at the problems, the method utilizes the microorganism to induce and generate calcium carbonate precipitation so as to repair the concrete cracks, is a novel biological method, is environment-friendly and is easy to operate. Through research, the bacillus pasteurii (Sporosarcina pasteurii) can repair concrete cracks by decomposing urea and rapidly generating calcium carbonate precipitates in the presence of a calcium source. And through patent retrieval, the research on repairing concrete cracks by using the bacillus pasteurianus is not yet available.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for repairing concrete cracks by decomposing urea and inducing calcium carbonate precipitation by using bacillus pasteurianus. According to the method, the bacillus pasteurii is used for decomposing urea, and then calcium carbonate precipitates are generated under the condition that a calcium source exists, so that concrete cracks are repaired.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

a biological repairing method for concrete cracks comprises the steps of sequentially injecting a bacillus pasteurianus solution, a urea solution and a soluble calcium salt solution into concrete cracks, enabling redundant liquid to seep out of the concrete cracks to stop operation, and repeating the operation after 1 hour, so that the concrete cracks are repaired.

The concentration of the soluble calcium salt solution is 1-2 mol/L.

The concentration of the urea solution is 1-2 mol/L.

The pasteuria bacillus solution is 1.2 x 10⁸cell·mL^-1。

The injection volumes of the pasteuria bacillus solution, the urea solution and the soluble calcium salt solution are the same.

The soluble calcium salt solution is Ca (NO)₃)₂Solution, calcium chloride solution or calcium acetate solution.

The culture temperature of the pasteurella bacillus solution is 10-40 ℃, and the culture time is 15-18 hours.

Preferably, the culture temperature of the pasteuria bacillus solution is 20 ℃.

The invention has the following beneficial effects and advantages:

(1) the invention takes bacteria, urea and soluble calcium salt as raw materials for producing calcium carbonate, and is cheap and easy to obtain.

(2) The bacterial repairing process is simple and easy to operate, and the process of producing calcium carbonate is a biological process and is environment-friendly.

(3) Ultrasonic pulse velocity detection analysis of the bacterially repaired concrete specimen revealed a decrease in propagation time of the repaired concrete specimen, indicating that the calcium carbonate sealed the cracks, thus allowing the ultrasonic waves to follow a more direct path through the sealed cracks.

(4) And (3) performing deflection analysis on the concrete sample after the bacterial remediation, and finding that the strength of the concrete sample is sequenced to the extent that the concrete sample after the bacterial remediation is larger than the concrete sample without the remediation, which shows that the strength of the concrete sample after the bacterial remediation is restored to a certain degree.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1: the invention has the overall technical route schematic diagram;

FIG. 2: the growth curve diagram of the pasteurella in the invention at different temperatures;

FIG. 3: the invention relates to a concrete sample entity diagram after repairing bacillus licheniformis;

FIG. 4: the invention relates to a permeability experimental device diagram;

FIG. 5: the transmission time schematic diagram of the concrete sample before and after the crack is repaired by the bacteria by the ultrasonic wave;

FIG. 6: load-mid-span deflection curves of the concrete sample BA after bacterial remediation and the unrepaired concrete sample W;

wherein BA refers to a concrete test piece after bacterial remediation; BB refers to the concrete specimen prior to bacterial remediation.

Detailed Description

For a better understanding of the nature of the invention, reference will now be made to the following examples taken in conjunction with the accompanying drawings.

Example 1

The invention provides a concrete crack repairing method, which comprises the steps of sequentially injecting a bacillus pasteurianus solution, a urea solution and a soluble calcium salt solution into a concrete crack, enabling redundant liquid to seep out of the concrete crack to stop operation, and repeating the operation after 1 hour, so that the concrete crack is repaired.

The concentration of the soluble calcium salt solution is 1 mol/L.

The concentration of the urea solution is 1 mol/L.

The injection volumes of the pasteuria bacillus solution, the urea solution and the soluble calcium salt solution are the same.

The soluble calcium salt solution is Ca (NO)₃)₂And (3) solution.

The culture temperature of the pasteurella bacillus solution is 20 ℃, and the culture time is 16 hours.

Example 2

The production process flow adopted by the invention is shown in figure 1, and the adopted technical scheme is as follows:

and (3) activating and culturing bacteria: activating and pouring the pasteurella freeze-dried powder purchased by the Beinanbiology into a flat plate, and carrying out expanded culture;

determining the optimal temperature and the optimal culture time for the growth of the bacteria: culturing Pasteurella pasteurianus at 6 temperatures (0 deg.C, 5 deg.C, 10 deg.C, 20 deg.C, 30 deg.C and 40 deg.C), and plotting growth curve to obtain optimal culture temperature of 20 deg.C and optimal culture time of 15-18 hr, the result is shown in FIG. 2;

determining the optimum of the Urea solution and the calcium nitrate solutionConcentration and proportion: three sets of experiments were designed, the first set of 10ml of 1mol/l urea solution, 10ml of 1mol/l Ca (NO)₃)₂The second group was 10ml of 2mol/l urea solution, 10ml of 2mol/l Ca (NO)₃)₂Solution and 10ml of bacterial solution, the third group being 1.5g urea, 15ml 1mol/l Ca (NO)₃)₂Solution and 10ml of bacterial solution. Mixing the above three experimental solutions, reacting completely, removing supernatant after calcium carbonate is completely precipitated, drying at 100 deg.C, and measuring CaCO₃Until constant weight, five replicates. The calcium carbonate quality of three experiments was compared and the results are shown in table 1;

TABLE 1 three groups of experimentally weighed CaCO₃Quality of

Urea solution, Ca (NO)₃)₂Solution and bacterial solution grouting: injecting the bacterial solution to be used into a concrete crack by using a pipette, then injecting an equal volume of 1mol/l urea solution, and finally adding an equal volume of 1mol/l calcium nitrate solution;

stopping the operation when excess water seeps out of the crack; after 1 hour, the above operation was repeated until the fracture was repaired completely.

The concrete sample of the crack after the bacterial remediation is shown in fig. 3, a constant water head permeability test is carried out, and through 24-hour observation, the crack of the sample after the bacterial remediation is found not to have any leakage, and a permeability experimental device is shown in fig. 4.

Ultrasonic pulse velocity detection analysis of the bacterially remediated concrete specimen, as shown in figure 5, found that the propagation time of the remediated concrete specimen was reduced, indicating that the calcium carbonate sealed the cracks, thus allowing the ultrasonic waves to follow a more direct path through the sealed cracks.

The concrete samples after bacterial remediation are subjected to deflection analysis, and the strength of the concrete samples is sequenced to be that the concrete samples after bacterial remediation are larger than the concrete samples without remediation, which shows that the strength of the concrete samples after bacterial remediation is restored to a certain degree, as shown in fig. 6.

Example 3

B, activating and culturing the bacillus pasteurii: activating and pouring the pasteurella freeze-dried powder purchased by the Beinanbiology into a flat plate, and carrying out expanded culture;

culturing the pasteuria bacillus at 20 ℃ for 15 hours;

urea solution, Ca (NO)₃)₂The optimal reaction ratio of the solution and the bacterial solution is as follows: the first group was 10ml of 1mol/l urea solution, 10ml of 1mol/l Ca (NO)₃)₂Solution and 10ml of bacterial solution;

cleaning concrete cracks: firstly, placing a concrete sample under a faucet for washing so as to remove some fragments in cracks, then scraping some other fragments by using a feeler gauge, placing the concrete sample under the faucet for washing again, and finally drying at room temperature; and sticking a waterproof adhesive tape at the bottom of the crack. The waterproof adhesive tape has the functions of allowing excessive water to pass through, and the repairing material is kept in the crack;

urea solution, Ca (NO)₃)₂Solution and bacterial solution grouting: injecting the bacterial solution to be used into a concrete crack by using a pipette, then injecting an equal volume of 1mol/l urea solution, and finally adding an equal volume of 1mol/l calcium nitrate solution;

stopping the operation when excess water seeps out of the crack; after 1 hour, the above operation was repeated until the fracture was repaired completely.

Example 4

B, activating and culturing the bacillus pasteurii: activating and pouring the pasteurella freeze-dried powder purchased by the Beinanbiology into a flat plate, and carrying out expanded culture;

culturing the Pasteurella pasteuriana at 20 ℃ for 18 hours;

urea solution, Ca (NO)₃)₂The optimal reaction ratio of the solution and the bacterial solution is as follows: the first group was 10ml of 1mol/l urea solution, 10ml of 1mol/l Ca (NO)₃)₂Solution and 10ml of bacterial solution;

cleaning concrete cracks: firstly, placing a concrete sample under a faucet for washing so as to remove some fragments in cracks, then scraping some other fragments by using a feeler gauge, placing the concrete sample under the faucet for washing again, and finally drying at room temperature; and sticking a waterproof adhesive tape at the bottom of the crack. The waterproof adhesive tape has the functions of allowing excessive water to pass through, and the repairing material is kept in the crack;

urea solution, Ca (NO)₃)₂Solution and bacterial solution grouting: injecting the bacterial solution to be used into a concrete crack by using a pipette, then injecting an equal volume of 1mol/l urea solution, and finally adding an equal volume of 1mol/l calcium nitrate solution;

stopping the operation when excess water seeps out of the crack; after 1 hour, the above operation was repeated until the fracture was repaired completely.

Example 5

B, activating and culturing the bacillus pasteurii: activating and pouring the pasteurella freeze-dried powder purchased by the Beinanbiology into a flat plate, and carrying out expanded culture;

culturing the Pasteurella pasteuriana at 20 ℃ for 18 hours;

the optimal reaction proportion of the urea solution, the calcium acetate solution and the bacterial solution is as follows: a first group of 10ml of 1mol/l urea solution, 10ml of 1mol/l calcium acetate solution and 10ml of bacteria solution;

cleaning concrete cracks: firstly, placing a concrete sample under a faucet for washing so as to remove some fragments in cracks, then scraping some other fragments by using a feeler gauge, placing the concrete sample under the faucet for washing again, and finally drying at room temperature; and sticking a waterproof adhesive tape at the bottom of the crack. The waterproof adhesive tape has the functions of allowing excessive water to pass through, and the repairing material is kept in the crack;

urea solution, calcium acetate solution and bacterial solution grouting: injecting the bacterial solution to be used into a concrete crack by using a pipette, then injecting an equal volume of 1mol/l urea solution, and finally adding an equal volume of 1mol/l calcium acetate solution;

stopping the operation when excess water seeps out of the crack; after 1 hour, the above operation was repeated until the fracture was repaired completely.

Example 6

B, activating and culturing the bacillus pasteurii: activating and pouring the pasteurella freeze-dried powder purchased by the Beinanbiology into a flat plate, and carrying out expanded culture;

culturing the Pasteurella pasteuriana at 20 ℃ for 18 hours;

the optimal reaction ratio of the urea solution, the calcium chloride solution and the bacteria solution is as follows: a first group of 10ml of 1mol/l urea solution, 10ml of 1mol/l calcium chloride solution and 10ml of bacteria solution;

cleaning concrete cracks: firstly, placing a concrete sample under a faucet for washing so as to remove some fragments in cracks, then scraping some other fragments by using a feeler gauge, placing the concrete sample under the faucet for washing again, and finally drying at room temperature; and sticking a waterproof adhesive tape at the bottom of the crack. The waterproof adhesive tape has the functions of allowing excessive water to pass through, and the repairing material is kept in the crack;

urea solution, calcium chloride solution and bacteria solution grouting: injecting the bacterial solution to be used into the concrete crack by using a pipette, then injecting 1mol/l urea solution with the same volume, and finally adding 1mol/l calcium chloride solution with the same volume;

stopping the operation when excess water seeps out of the crack; after 1 hour, the above operation was repeated until the fracture was repaired completely.