COLOR-ADJUSTABLE REPAIRING AGENT AND PREPARATION METHOD THEREFOR, AND CONCRETE CONTAINING REPAIRING AGENT

Abstract

A color-adjustable repairing agent and a preparation method therefor, and concrete containing the repairing agent are disclosed in the present invention; the repairing agent is a mixture of microbial powder, dopamine and a calcium source immobilized by cement; and according to total mass of the mixture, a mass percentage of the microbial powder is 44%-54%, a mass percentage of the dopamine is 1%-5%, and a mass percentage of the calcium source is 44%-54%; according to the present invention, dopamine is mixed into a microbial self-repairing agent, a cement-immobilized microbial self-repairing agent is used for preparing repairing agent particles, a crack area of microbial self-repairing concrete is repaired, and repairing performance of the concrete and a color of a repairing product of the crack area are tested.

Claims

1. A color-adjustable repairing agent, being a mixture of microbial powder, dopamine and a calcium source immobilized by cement, wherein according to total mass of the repairing agent, a mass percentage of the microbial powder is 44%-54%, a mass percentage of the dopamine is 1%-5%, and a mass percentage of the calcium source is 44%-54%.

2. The color-adjustable repairing agent according to claim 1, wherein the microbial powder is selected from Bacillus mucilaginosus or Bacillus alkalophilus.

3. The color-adjustable repairing agent according to claim 1, wherein the calcium source comprises one or more types of solid powder of calcium formate, calcium chloride and calcium phosphate.

4. The color-adjustable repairing agent according to claim 1, wherein the cement comprises sulphoaluminate cement or portland cement.

5. A preparation method for the color-adjustable repairing agent according to claim 1, comprising the following steps: (1) mixing microbial powder, dopamine and a calcium source, and performing uniform stirring to obtain mixed powder for later use; (2) taking a proper amount of an adhesive substance, spraying distilled water on a surface of the adhesive substance, and pouring the adhesive substance into a sugarcoating machine; and spraying the mixed powder prepared in the step (1) and water mist into the sugarcoating machine in batches for powder-coating granulation, and sieving particles after granulation; and (3) pouring the sieved particles into the sugarcoating machine again, spraying cement powder and water mist into the sugarcoating machine in batches for powder-coating granulation, and performing sieving to obtain repairing agent particles after granulation.

6. The preparation method for the color-adjustable repairing agent according to claim 5, wherein in the step (1), a mass ratio of the microbial powder to the dopamine to the calcium source is 10-45:10-45:1.

7. The preparation method for the color-adjustable repairing agent according to claim 5, wherein in the step (2), the adhesive substance is sucrose particles.

8. The preparation method for the color-adjustable repairing agent according to claim 5, wherein in the step (2), a particle size after sieving is 1.75 mm-2.36 mm; and in the step (3), a particle size after sieving is 3.5 mm-4.0 mm.

9. The preparation method for the color-adjustable repairing agent according to claim 5, wherein after the step (3), the preparation method further comprises curing the repairing agent particles, wherein a curing process comprises: making the repairing agent particles stand for 45 h-50 h in a ventilation environment with a constant temperature of 20? C.-30? C., and spraying water mist on a surface of the repairing agent every 6 h-8 h, to keep the surface wet.

10. Concrete, obtained by mixing the repairing agent according to claim 1 instead of fine aggregate, wherein the mixing amount of the repairing agent is 0.5%-4%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a schematic diagram of a crack repairing site of a sample with repairing agent particles containing dopamine according to Example 1;

[0022] FIG. 2 is a schematic diagram of a crack repairing site of a sample with repairing agent particles containing no dopamine according to Example 1;

[0023] FIG. 3 is a schematic diagram of a crack repairing site of a sample with repairing agent particles containing dopamine according to Example 2;

[0024] FIG. 4 shows a variation of an ultrasonic velocity of a concrete sample with a repairing time in Example 3;

[0025] FIG. 5 shows a variation of a recovery rate of water penetration resistance of a concrete sample with a repairing time in Example 3;

[0026] FIG. 6 shows synthetic product powder mixed with dopamine in Example 4;

[0027] FIG. 7 shows synthetic product powder without dopamine in Example 4; and

[0028] FIG. 8 is an infrared analysis spectrum of a mineralized product in Example 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The technical solution of the present invention will be further elaborated hereafter in conjunction with accompanying drawings and the examples.

Example 1

[0030] (1) Bacillus mucilaginosus powder, calcium formate, dopamine were mixed in a mass ratio of 30:30:1 to prepare mixed powder, sucrose was taken as a core, sucrose particles were spread, water mist was sprayed on surfaces of the particles, the particles were poured into a sugarcoating machine, the mixed powder and water mist were sprayed into the sugarcoating machine in batches for powder-coating granulation, and repairing agent particles were sieved to obtain particles with a particle size of 1.75 mm-2.36 mm after granulation. [0031] (2) The particles were coated with sulphoaluminate cement by using the sugarcoating machine again, sieved particles were poured into the sugarcoating machine again, sulphoaluminate cement and water mist were sprayed into the sugarcoating machine in batches for powder-coating granulation, and repairing agent particles were sieved to obtain particles with a particle size of 3.5 mm-4.0 mm, that is, the repairing agent, after granulation. [0032] (3) The repairing agent particles were placed in a ventilation environment with a constant temperature of 20? C. for curing for 48 h, and water mist was sprayed on a surface of a carrier every 6 h to keep the surface of the carrier moist. [0033] (4) 1037 g/L of P.Math.O42.5 ordinary portland cement, 47 g/L of the repairing agent and 546 g/L of water were weighed, a pure slurry sample was mixed, the pure slurry sample was cured for 3 d under standard conditions, and a crack was made on the sample. [0034] (5) The cracked pure slurry sample was cured in water at 20? C. for 7 d, a crack area (as shown in FIG. 1) was observed with a stereo microscope, the crack was filled with a microbial mineralized product, and it can be seen that mixing of dopamine has little effect on a crack surface repairing effect. Compared with a crack repairing area of the sample without dopamine (as shown in FIG. 2), a repairing product of the sample with dopamine in the crack area had an off-white color, and a color difference between the repairing product and the concrete matrix decreased, such that mixing of dopamine can adjust the color of the repairing product.

[0035] The repairing product obtained after color adjustment was extracted, dried, ground, and detected by using a Fourier transform infrared absorption spectrometer, and feasibility of color adjustment on the mineralized product by dopamine was analyzed. An infrared spectrum of the obtained mineralized product is shown in FIG. 8. There is an N . . . HO hydrogen bond oscillation peak at a wavenumber of 3405.47 cm.sup.?1, indicating that dopamine and calcium carbonate are connected by a hydrogen bond, to form an organic-inorganic composite structure.

Example 2

[0036] (1) Bacillus alkalophilus powder, calcium chloride, dopamine were mixed in a mass ratio of 10:10:1 to prepare mixed powder, sucrose was taken as a core, sucrose particles were spread, water mist was sprayed on surfaces of the particles, the particles were poured into a sugarcoating machine, the mixed powder and water mist were sprayed into the sugarcoating machine in batches for powder-coating granulation, and repairing agent particles were sieved to obtain particles with a particle size of 1.75 mm-2.36 mm after granulation. [0037] (2) The particles were coated with portland cement by using the sugarcoating machine again, sieved particles were poured into the sugarcoating machine again, portland cement and water mist were sprayed into the sugarcoating machine in batches for powder-coating granulation, and repairing agent particles were sieved to obtain particles with a particle size of 3.5 mm-4.0 mm, that is, the repairing agent, after granulation. [0038] (3) The repairing agent particles were placed in a ventilation environment with a constant temperature of 30? C. for curing for 50 h, and water mist was sprayed on a surface of a carrier every 8 h to keep the surface of the carrier moist. [0039] (4) 347 g/L of P.Math.O42.5 ordinary portland cement, 40 g/L of the repairing agent, 746 g/L of river sand, 1187 g/L of basalt stone, and 170 g/L of water were weighed, a concrete sample was mixed, the concrete sample was cured for 3 d under standard conditions, and a crack was made on the sample. [0040] (5) The cracked pure slurry sample was cured in water at 20? C. for 7 d, a repairing situation was observed with a stereo microscope, and a crack repairing area was shown in FIG. 3.

Example 3

[0041] (1) Bacillus mucilaginosus powder, calcium phosphate, dopamine were mixed in a mass ratio of 45:45:1 to prepare mixed powder, sucrose was taken as a core, sucrose particles were spread, water mist was sprayed on surfaces of the particles, the particles were poured into a sugarcoating machine, the mixed powder and water mist were sprayed into the sugarcoating machine in batches for powder-coating granulation, and repairing agent particles were sieved to obtain particles with a particle size of 1.75 mm-2.36 mm after granulation. [0042] (2) The particles were coated with sulphoaluminate cement by using the sugarcoating machine again, sieved particles were poured into the sugarcoating machine again, sulphoaluminate cement and water mist were sprayed into the sugarcoating machine in batches for powder-coating granulation, and repairing agent particles were sieved to obtain particles with a particle size of 3.5 mm-4.0 mm, that is, the repairing agent, after granulation. [0043] (3) The repairing agent particles were placed in a ventilation environment with a constant temperature of 25? C. for curing for 45 h, and water mist was sprayed on a surface of a carrier every 7 h to keep the surface of the carrier moist. [0044] (4) 347 g/L of P.Math.O42.5 ordinary portland cement, 23 g/L of the repairing agent, 764 g/L of river sand, 1187 g/L of basalt stone, and 170 g/L of water were weighed, a concrete sample was mixed, the concrete sample was cured for 3 d under standard conditions, and a crack was made on the sample. [0045] (5) The cracked pure slurry sample was cured in water at 20? C., when a curing time was 7d, 14d and 28d, a bonding situation of a repairing product in the concrete crack was analyzed by ultrasonic velocity detection, and as shown in FIG. 4, the bonding situation was compared with that of a sample with repairing agent particles containing dopamine and that of a sample without repairing agent particles for analysis. An ultrasonic velocity of the concrete sample with dopamine was similar to that of the concrete sample without dopamine, indicating that the mixing of dopamine has little effect on bonding of a repairing product in a concrete crack. A filling situation of the repairing product in the concrete crack was analyzed by means of detection of a recovery rate of water penetration resistance, and as shown in FIG. 5, the filling situation was compared with that of the sample with repairing agent particles containing dopamine and that of the sample without repairing agent particles for analysis. The recovery rate of water penetration resistance of the concrete sample with dopamine was slightly lower than that of the sample without dopamine, and much higher than that of the sample without repairing agent particles, indicating that mixing of dopamine has little effect on filling of a repairing product in a concrete crack.

Example 4

[0046] In order to verify reaction of dopamine with a microbial mineralized product, the following experiment is performed: [0047] (1) Water was added to dissolve and mix bacterial liquid, a calcium source and dopamine powder, and reaction liquid was prepared. [0048] (2) The liquid was placed in a light-proof environment at a normal temperature for standing reaction for 7 d, and suspension containing the mineralized product was obtained after the mineralization reaction is finished. [0049] (3) The suspension was filtered, and a precipitate was washed with deionized water and absolute ethyl alcohol. [0050] (4) The precipitate was dried to obtain synthetic product powder. [0051] (5) The synthetic product powder (as shown in FIG. 5) with dopamine (PDA) was compared with synthetic product powder (as shown in FIG. 6) without dopamine for analysis, the synthetic product containing dopamine appeared brown-gray, and the synthetic product without dopamine appeared white. Gray values of the synthetic products were detected by ImageJ software (a gray value of black is 0, and a gray value of white is 255). The gray values of the two synthetic products were 110.136 and 177.489 respectively. Dopamine can reduce the gray value of the synthetic product and make the product darker.