Grouting material for repairing ancient city wall, preparation method and grouting device

Abstract

The invention provides an ancient city wall repairing grouting material, a preparation method and a grouting device, and relates to the field of city wall repairing, the grouting material comprises the following components by weight: 50-60 parts of slaked lime, 15-20 parts of cement, 25-60 parts of mineral powder, 90-120 parts of sea sand, 10-30 parts of modified shell powder, 30-40 parts of water, 10-15 parts of glutinous rice slurry, 1-3 parts of alum, 7-9 parts of a bacillus pasteurii liquid, and 7-8 parts of a mineralization reaction liquid. The grouting device comprises a grouting device body, a discharging pipe and a grouting supporting mold, and a stirring mechanism is arranged at the top of the grouting device body; the grouting supporting mold comprises a base, a main frame, a plurality of adjusting plates and a plurality of extension rods. Through the synergistic effect of the microorganisms, the modified shells and the mineral powder, efficient preparation of the ancient city wall slurry from old to old, modification treatment of shell carriers and regulation and control of the acid-base environment of the microorganism slurry are achieved, urease-driven carbonate precipitation generation and color fixation are achieved, and a new solution is provided for the microorganism grouting technology.

Description

Technical Field

[0001] The present invention relates to the field of city wall repair, and in particular to a grouting material for repairing ancient city walls, a preparation method and a grouting device. Background Art

[0002] As a vital component of historical and cultural heritage, the restoration of the ancient city wall must balance structural stability with the preservation of its original historical appearance. While traditional microbial induced carbonate precipitation (MICP) technology offers environmental advantages, traditional MICP slurries suffer from low strength, poor uniformity, and uncontrollable color. Microorganisms are easily inactivated in high temperatures or acid rain, and traditional processes lack stable temperature control and bacterial carrier protection mechanisms, resulting in uncontrollable color effects in the restoration. Existing slurries fail to consider the alkaline environment requirements of ancient building restoration, nor the "repair the old with the old" approach to aging ancient buildings.

[0003] In addition, existing grouting devices are not suitable for the repair of ancient city walls. Patent CN107859346A discloses a portable rechargeable caulking gun, and patent CN208329662U discloses a handheld electric grouting gun for decoration projects. Although they can be used to repair ordinary buildings, neither of them takes into account the construction characteristics of microbial slurry and the appropriate stirring temperature. Currently, the repair devices on the market are mainly improved to prevent leaks. The grouting device requires the slurry to be stirred and then placed inside the grouting device. In the outdoor repair of ancient city walls, there is no corresponding equipment for on-site temperature control and mixing of raw materials. In addition, the strength and repair capabilities of existing city wall repair grouting materials still need to be improved. Summary of the Invention

[0004] In order to solve the deficiencies of the above-mentioned prior art, the present invention provides a grouting material for repairing ancient city walls, a preparation method and a grouting device. The grouting material for repairing ancient city walls of the present invention starts with the regulation of mineral powder, sea sand and the living environment of microorganisms. Through long-term experiments, the balance limit of the ratio of the two is found, and an ancient city wall repair slurry that takes into account both strength and aging effect and its preparation method are designed. The modified shell can provide a reliable carrier for the adaptability of microorganisms, and the sea sand provides mechanical support as an inert aggregate. The silanol groups (Si-OH) on its surface adsorb Ca 2+, promoting the directional crystallization of calcium carbonate (CaCO3), and its salt content has the effect of alkali-resistant aging of the slurry. "Repairing the old with the old" does not mean completely using ancient materials for repair, but on the basis of using the ancient repair material - slaked lime as much as possible, a variety of methods are used to adjust the color and pH of the microbial slurry to create the vicissitudes of the ancient city wall. The present invention comprehensively regulates the color of the repair slurry and maximizes carbon sequestration through microbial mineralization, which is in line with the concept of green restoration. It solves the core pain points of the traditional ancient city wall repair slurry, such as new color, low strength, and poor construction efficiency, and provides an efficient, environmentally friendly and sustainable solution for the restoration of ancient city walls. At the same time, the grouting device proposed in the present invention can adapt to the requirements of on-site low-temperature stirring (adjustable temperature) under the premise of the design of this grouting material, to ensure the activity of microorganisms in the alkaline encounter environment. It also realizes the steam injection treatment of dust in the gaps inside the city wall before grouting, which can improve the bonding effect and color performance of the microbial slurry.

[0005] The color of the reaction between Bacillus pasteurianus and mineral powder is mainly determined by the microbial activity affected by the environmental pH and the metal composition of the mineral powder. The modification of the shell carrier and the regulation of the acid-base environment of the slurry realize the urease-driven carbonate precipitation and color fixation, which has the potential for both biomineralization and environmental remediation.

[0006] Specifically, on the one hand, the present invention provides a city wall repair grouting material, comprising the following ingredients in parts by weight: 50-60 parts of slaked lime, 15-20 parts of cement, 25-60 parts of mineral powder, 7-9 parts of Bacillus pasteurianus liquid, 10-30 parts of modified shell powder, 30-40 parts of water, 10-15 parts of glutinous rice paste, 1-3 parts of alum, 90-120 parts of sea sand, and 7-8 parts of mineralization reaction liquid;

[0007] The mineralization reaction solution is 0.5 mol / L to 1.0 mol / L calcium chloride solution and 0.5 mol / L to 1.0 mol / L urea solution in a ratio of 1:1, stirred and mixed for 10 to 30 seconds to form a mineralization reaction solution;

[0008] Using modified shell powder as a mixed bacterial carrier to form an acid-base modified shell carrier microbial growth environment, Bacillus pasteurianus decomposes urea to produce carbonate CO3 through urease catalysis. 2- and ammonium NH4 + , CO3 2- Combined with the metal cations in the mineral powder to form carbonate precipitation, in the microbial growth environment of the acid-base modified shell carrier, the mineral components dissolve and precipitate, causing color changes. By adjusting the weight ratio of slaked lime, cement, mineral powder, Bacillus pasteurianus liquid and modified shell powder, the color depth of the grouting material can be adjusted. The color adjustment model is as follows:

[0009]

[0010] Wherein, C is the change in the color of the grouting material, C0 is the basic color value of the grouting material, a, b, c, d, e are the target adjustment weight portions of slaked lime, cement, mineral powder, Bacillus pasteurianus solution and modified shell powder respectively, and the value ranges of a, b, c, d, e are: a∈[50,60], b∈[15,20], c∈[25,60], d∈[7,9], e∈[10,30] respectively; a0, b0, c0, d0, e0 are the basic weight portions of slaked lime, cement, mineral powder, Bacillus pasteurianus solution and modified shell powder respectively, and k a 、k b 、k c 、k d 、k e They are the proportion adjustment coefficients of slaked lime, cement, mineral powder, Bacillus pasteurianus liquid and modified shell powder.

[0011] Preferably, the pH value of the Bacillus pasteurianus liquid is 8.0-9.2, the slaked lime is slaked lime with a calcium content of 95%, the alum is edible alum powder with a particle size of 50-150 microns, the slag is S95 grade with a sulfur content of 3.5-4%, the sea sand has a chloride ion content of 0.03%-0.06% by mass, a particle size of 0.15mm-2.36mm, a fineness modulus of 2.3-3.0, a pH value of 7.0-7.5, and the cement is P﹒O42.5 cement.

[0012] Preferably, the values of a0, b0, c0, d0, and e0 are 60, 15, 45, 8, and 20 respectively. a 、k b 、k c 、k d 、k e The values of are fitted by the least squares method, and the values after fitting are 0.3, 0.6, 0.8, 1, and 0.6 respectively.

[0013] In a second aspect, the present invention provides a method for preparing a grouting material for repairing an ancient city wall, comprising the following steps:

[0014] S1. Preparing Bacillus pasteurianus: expanding the culture of Bacillus pasteurianus and acclimating the Bacillus pasteurianus using a five-gradient acclimation method to obtain an acclimated bacterial liquid;

[0015] S2, preparing modified shell powder as a mixed bacteria carrier;

[0016] S3. Preparing a solidified slurry reaction liquid: adding the acclimated bacterial liquid and the mineralization reaction liquid to a stirring device according to a target weight ratio and stirring for 30 to 60 seconds to obtain a solidified slurry reaction liquid. The solidified slurry reaction liquid is divided into a first solidified slurry reaction liquid and a second solidified slurry reaction liquid. The first solidified slurry reaction liquid is used for subsequent grouting material preparation, and the second solidified slurry reaction liquid is used for coating the surface of the grouting material after grouting.

[0017] S4. Dry material premixing: adding slaked lime powder, cement, slag, modified shell powder and sea sand to the grouting device according to the target weight ratio and mixing and stirring;

[0018] S5, initial mixing: take 40% of the target weight of water and glutinous rice paste in a closed container and shake and mix thoroughly, then add it to the grouting device and stir for t1 second;

[0019] S6, secondary mixing: take 60% of the target weight of water and alum into a sealed container for pre-dissolution, shake and homogenize, add to the grouting device and stir for 2 seconds;

[0020] S7. Biomineralization treatment: slowly add the first solidified slurry reaction liquid prepared in S3 into the grouting device, stir at 2-8° C. for 3 seconds, and finally obtain the composite cementitious material grouting material.

[0021] Preferably, S1 specifically includes the following sub-steps:

[0022] S11. Bacterial expansion: Prepare a basal medium containing 10-12 g / L peptone, 3-5 g / L beef extract, and 60-65 g / L urea, inoculate with Bacillus pasteurianus, and place in a constant temperature shaker at 35-40°C and shake at 200-220 rpm;

[0023] S12. Growth monitoring: Use an ultraviolet spectrophotometer to dynamically monitor bacterial growth until the OD600 value reaches 0.5-1.0;

[0024] S13. Bacteria collection: centrifuge the bacterial suspension, collect the bacterial sludge, wash it with sterile saline, and place it in an 80°C water bath for 10-15 min. The final bacterial suspension concentration is adjusted to 1×10^8 CFU / mL and stored at -20°C to maintain activity.

[0025] S14. Five-gradient acclimation: The Bacillus pasteurianus liquid was serially passaged at a 1% inoculum size through five increasing salt concentration gradient media, with the gradient concentrations being 4.90±0.5g / L, 9.80±0.5g / L, 14.70±0.5g / L, 19.60±0.5g / L, and 24.53±0.5g / L, respectively; each gradient was cultured until the OD600 stabilized and then transferred to the next gradient until the five gradients were completed.

[0026] Preferably, in the dry material premix S3, slaked lime powder, cement and sea sand are added to the grouting device and stirred at a speed of 30 r / min for 4 seconds to mix the dry materials, and then stirred at a speed of 60 r / min for 5 seconds, wherein t1 <t2<t3,t2=1.5t1,t3=1.5t2,t4=2t5。

[0027] Preferably, S2 specifically includes the following sub-steps: S21, after washing the shells, placing them in an oven at a temperature of 80±2°C, drying them for 4-4.5 hours, and then crushing and sieving them to retain shell powder with a particle size of 0.3-0.6 mm;

[0028] S22, immersing the shell powder obtained in S21 in a 30wt% citric acid solution, treating it with ultrasonic immersion for 40 to 60 minutes, and washing it with water until it becomes neutral;

[0029] S23, soaking the shell powder obtained in S22 four times:

[0030] First time: soak in 18-25wt% NaOH solution for 15-30 minutes, then wash with water until neutral;

[0031] Second time: soak in 5-12wt% NaOH solution for 30-40h, then wash with water until neutral;

[0032] The third time: soak in 20-30wt% citric acid solution for 2-4 hours, then wash with water until neutral;

[0033] Fourth time: soaking in 40-60wt% NaOH solution for 20-30h, washing with water until neutral to obtain shell powder after four soakings;

[0034] S24. Place the shell powder obtained in S23 in an industrial microwave oven and process for 60 minutes, then take it out and cool it to room temperature for later use.

[0035] In a third aspect, the present invention provides a grouting device for city wall repair grouting material, which includes a grouting device body, a discharge pipe, and a grouting support mold, wherein a stirring mechanism is provided on the top of the grouting device body;

[0036] The stirring mechanism includes a mounting tube, a motor, a movable rod, a first spiral blade, a connecting tube, a funnel, a fixed block and a movable plate. The connecting tube and the mounting tube are arranged on the top of the grouting device body, the motor is arranged inside the mounting tube, the output end of the motor is provided with a movable rod, the outside of the movable rod is provided with a first spiral blade, the top of the connecting tube is provided with a funnel, the inside of the connecting tube is fixedly provided with a fixed block, and the outside of the fixed block is hinged with a movable plate; a cooling mechanism is provided on the outside of the stirring mechanism, and the cooling mechanism is connected to a PLC controller. The PLC controller obtains real-time temperature signals through a temperature sensor and outputs control signals to the cooling mechanism after logical operation;

[0037] The grouting support mold includes a base, a main frame, multiple adjustment plates and multiple extension rods. The first end of the main frame is fixedly connected to the base, and the second end, the third end and the fourth end of the main frame are respectively connected to the adjustment plates by means of extension rods. The first end of the extension rod can be telescopically connected to the main frame, and the second end of the extension rod is hinged to the adjustment plate.

[0038] Preferably, a disassembly and assembly mechanism is provided on the outside of the grouting device body, including an external threaded tube, an internal threaded sleeve, a bellows, a one-way air intake valve, an inner tube, a rotating rod and a second threaded blade, the outside of the discharge pipe is fixedly connected with the external threaded tube, the outside of the external threaded tube is provided with an internal threaded sleeve, the outside of the internal threaded sleeve is provided with a bellows, the outside of the bellows is fixedly connected with the one-way air intake valve, the interior of the grouting device body is sleeved with the inner tube, the interior of the grouting device body is provided with a rotating rod, and the outside of the rotating rod is fixedly connected with the second threaded blade; a rotating cavity is opened inside the inner tube, the rotating rod is located inside the rotating cavity and has a gap with the rotating cavity, a shaft sealing assembly is provided inside the inner tube, the shaft sealing assembly is movably connected to the rotating rod, two sliding bars are fixedly installed on the outside of the inner tube, a sliding groove adapted to the two sliding bars is opened inside the grouting device body, a clamping block is hinged on the outside of the grouting device body, and the clamping block is movably connected to the grouting device body by means of a first torsion spring, and a feed port is provided at the top of the inner tube, and the feed port is connected to the bottom of the connecting tube.

[0039] Preferably, the heat preservation mechanism includes an installation box, a semiconductor refrigeration sheet, a temperature sensor, and a heat dissipation fan. The interior of the installation box is fixedly installed with a semiconductor refrigeration sheet, the interior of the installation box is fixedly installed with a temperature sensor, the exterior of the installation box is fixedly installed with a heat dissipation fan and a connecting pipe, and the output end of the PLC controller is connected to the input end of the semiconductor refrigeration sheet.

[0040] The PLC controller collects the temperature PV in real time through the temperature sensor, compares it with the set value SV, calculates the deviation and outputs a control signal to adjust the power of the semiconductor refrigeration chip.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The Bacillus pasteurianus colonies of the present invention are usually milky white or light yellow, and urease catalyzes the decomposition of urea to produce carbonate (CO3 2- ) and ammonium ion (NH4 + ), CO3 2- With the metal cations in the mineral powder (such as Ca 2+ Mg 2+ ) combines to form carbonate precipitates. In the microbial growth environment of the acid-base modified shell carrier, the color change caused by the dissolution and precipitation of mineral components is the key to the research and development of the present invention. The present invention can adjust the overall color tone and alkalinity of the lime mortar by mixing gray mineral powder and light gray silicate cement in proportion. It is caused by the reaction of sulfides in part of the slag powder with compounds in silicate cement, mainly producing trace FeS and MnS hydrated compounds, which are dark blue. This local "blue-green color" can form a certain aging effect and will not affect the performance of concrete, such as strength, low permeability and durability.

[0043] (2) The grouting material of the present invention adds an organic microbial slurry reaction liquid, which can change the reflectivity of the particle surface and achieve fine-tuning of the color. Through the alkali control inside the slurry, the salts in the sea sand are alkali-aged, and the slurry reaction liquid applied externally plays a role in wrapping and fixing the color, thereby inhibiting the slurry from cracking. Through the synergistic effect of slag, sea sand, cement, and microorganisms on lime, the color control of the ancient city wall repair slurry is achieved, and the carbon fixation repair effect is enhanced.

[0044] (3) The slurry grouting device of the present invention can keep the temperature inside the funnel at 2-8°C at any time by providing a heat preservation mechanism. The low temperature environment of 2-8°C can slow down its metabolic activity, prolong the active time of the initial alkali contact of Bacillus pasteurianus, and ensure the stirring effect of the full fusion reaction of the bacterial liquid and the slurry. The slurry grouting device of the present invention connects the external threaded pipe with the internal threaded sleeve, and then repeatedly presses the bellows to inflate the interior of the grouting device body, which can quickly clean the residual material inside the gap of the ancient city wall. Then, the entire inner pipe is inserted and connected to the connecting tube through the feed port, and the second threaded blade is continuously rotated to extrude the slurry. The disassembly and assembly mechanism can perform dust blowing and dust removal treatment on the interior of the grouting device after use, which is beneficial to improving the slurry bonding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the process of preparing the grouting material of the present invention;

[0046] Figure 2 It is a three-dimensional diagram of the structure of the present invention;

[0047] Figure 3 It is a front cross-sectional view of the present invention;

[0048] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0049] Figure 5 For the present invention Figure 3 Enlarged view of point B in the middle;

[0050] Figure 6 This is a top sectional view of the connecting tube of the present invention;

[0051] Figure 7 This is a diagram of the external structure of the inner tube of the present invention;

[0052] Figure 8 This is a schematic structural diagram of the internal thread sleeve of the present invention;

[0053] Figure 9 This is a diagram of the external structure of the bellows of the present invention;

[0054] Figure 10 For the present invention Figure 3 Enlarged view of point C in the middle;

[0055] Figure 11 This is a schematic diagram of the structure of the external cooling mechanism of the mounting cylinder of the present invention;

[0056] Figure 12 This is a three-dimensional structural diagram of the grouting support mold of the present invention;

[0057] Figure 13 This is a side view of the grouting support mold of the present invention;

[0058] Figure 14 This is the principle diagram of the adaptive fuzzy PID of the present invention;

[0059] Figure 15 Schematic diagram of the comparison between the slurry in a specific embodiment of the present invention after 28 days and the ancient building color card;

[0060] Figure 16 Schematic diagram of the comparison between the restoration of the Ming Great Wall and the ancient building color card in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0061] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0062] On the one hand, the present invention provides a city wall repair grouting material, which includes the following ingredients in parts by weight: 50 to 60 parts of slaked lime, 15 to 20 parts of cement, 25 to 60 parts of mineral powder, 7 to 9 parts of Bacillus pasteurianus liquid, 10 to 30 parts of modified shell powder, 30 to 40 parts of water, 10 to 15 parts of glutinous rice paste, 1 to 3 parts of alum, 90 to 120 parts of sea sand and 7 to 8 parts of mineralization reaction liquid.

[0063] The mineralization reaction solution is prepared by mixing 0.5 mol / L to 1.0 mol / L calcium chloride solution and 0.5 mol / L to 1.0 mol / L urea solution in a ratio of 1:1, and stirring for 10 to 30 seconds to form a mineralization reaction solution.

[0064] Modified shell powder is used as a mixed bacterial carrier to form an acid-base modified shell carrier microbial growth environment. By increasing or decreasing the proportion of modified shell powder on the basis of 20 parts of modified shell powder, the color of the grouting material is deepened or lightened. Bacillus pasteurianus decomposes urea to generate carbonate CO3 through urease catalysis. 2- and ammonium NH4 + , CO3 2- Combining with the metal cations in the mineral powder to form carbonate precipitates, the mineral components dissolve and precipitate in the microbial growth environment of the acid-base modified shell carrier, causing color changes. When the ratio of cement, mineral powder, Bacillus pasteurianus liquid, slaked lime, and modified shell powder is 15:45:8:30:20, it is the balance point for the old restoration color band. When the proportion of modified shell powder is increased, the color of the grouting material is deepened, and when the proportion of modified shell powder is reduced, the color of the grouting material is lighter.

[0065] In specific applications, the color of the grouting material can be modeled. Using modified shell powder as a carrier for mixed bacteria to form a microbial growth environment of an acid-base modified shell carrier, Bacillus pasteurii catalyzes the decomposition of urea through urease to generate carbonate CO3 2- and ammonium NH4 + , CO3 2- combines with metal cations in the mineral powder to form carbonate precipitates. In the microbial growth environment of the acid-base modified shell carrier, the dissolution and precipitation of mineral components cause color changes. By adjusting the weight ratios of hydrated lime, cement, mineral powder, Bacillus pasteurii liquid, and modified shell powder, the color depth of the grouting material can be adjusted. The adjustment model is as follows:

[0066]

[0067] where C is the change in the color of the grouting material, C0 is the base color value of the grouting material, and a, b, c, d, and e are the target weight parts of hydrated lime, cement, mineral powder, Bacillus pasteurii liquid, and modified shell powder respectively. The value ranges of a, b, c, d, and e are: a ∈ [50, 60], b ∈ [15, 20], c ∈ [25, 60], d ∈ [7, 9], e ∈ [10, 30]; a0, b0, c0, d0, and e0 are the base weight part values of hydrated lime, cement, mineral powder, Bacillus pasteurii liquid, and modified shell powder respectively, and k a , k b , k c , k d , k e are the proportional adjustment coefficients of hydrated lime, cement, mineral powder, Bacillus pasteurii liquid, and modified shell powder respectively. In specific application examples, the values of a0, b0, c0, d0, and e0 are 60, 15, 45, 8, and 20 respectively. The values of k a , k b , k c , k d , k e are obtained by fitting through the least squares method. After fitting, the values are 0.3, 0.6, 0.8, 1, and 0.6 respectively. When C < C0, the color of the grouting material is lighter than the base color value; when C > C0, the color of the grouting material is darker than the base color value.

[0068] In a specific embodiment, the pH value of the Bacillus pasteurii liquid is 8.0 - 9.2, the hydrated lime is hydrated lime with a calcium content of 95%, the alum is edible alum powder with a particle size of 50 - 150 microns, the slag is S95 grade with a sulfur content of 3.5 - 4%, the chloride ion content of the sea sand is 0.03% - 0.06% by mass fraction, the particle size is 0.15 mm - 2.36 mm, the fineness modulus is 2.3 - 3.0, the pH value is 7.0 - 7.5, and the cement is P﹒O42.5 cement.

[0069] The chloride ion content of the sea sand is 0.03% to 0.06% by mass, the particle size is 0.15mm to 2.36mm, the fineness modulus is 2.3 to 3.0, the pH value is 7.0 to 7.5, the cement is PII52.5 cement, the slaked lime is slaked lime with a calcium content of 95%, and the alum is edible alum powder with a particle size of 50-150 microns.

[0070] The present invention uses Bacillus pasteurianus to decompose urea, and microorganisms induce carbonate precipitation in slag, cement, and lime. MICP:

[0071]

[0072] Ca2+ adsorbed on Si-OH groups and CO3 in solution 2- Combine to form calcite-type calcium carbonate crystals:

[0073] Ca 2+ +CO3 2— →CaCO3↓

[0074]

[0075] Bacillus pasteurianus produces CO3 by decomposing urea during the MICP process 2- , combines with calcium and magnesium ions in slag in an alkaline environment to form calcium carbonate and magnesium carbonate, a dark gray precipitate. This process involves indirect fixation of CO2:

[0076]

[0077] Ca 2+ +CO3 2- →CaCO3↓

[0078] The present invention utilizes the synergistic effect of slag and cement to control the color of the lime slurry as a whole. The sulfides in the slag (such as FeS2, MnS2, etc.) are hydrolyzed in an alkaline environment (cement hydration produces OH-) to release S 2- ion:

[0079] FeS2+2H2O→Fe 2+ +2SH - +H2O2 (partial oxidation)

[0080] MnS2+2H2O→Mn 2+ +2SH - +H2O2

[0081] S 2- With Fe in slag and cement 2+ 、Mn 2+Combined with the formation of sulfide precipitation, it promotes the formation of FeS and MnS, forming a blue-green mottled aging effect on the newly restored ancient building walls:

[0082] Fe 2+ +S 2- →FeS↓

[0083] Mn 2+ +S 2- →MnS↓

[0084] Oxidation reaction rate: Oxygen participates in the oxidation of sulfides, which may affect the stability of FeS and MnS (such as the generation of brown products such as Fe(OH)3).

[0085] The key factors influencing the above color control are: 1. Slag dosage: The higher the sulfide content in the slag, the more pronounced the bluish-green effect. Therefore, S95-grade slag with a sulfur content of 3.5-4% was selected. 2. Porosity and curing conditions: The high porosity created by the incorporation of a low-temperature, stirred, high-survival microbial slurry reaction solution accelerates the reaction; the encapsulated curing environment of the externally applied microbial slurry promotes the formation of hydrated compounds. This results in a color-modified slurry for the ancient city wall, utilizing the microbial Bacillus pasteurianus to achieve the "repair the old with the old."

[0086] Brushing a layer of bacterial liquid on the outside plays a role in fixing the color and stabilizing the alkaline environment. Because the bacterial liquid is white or light yellow, the more layers you brush on the outside, the lighter the color of the slurry, and vice versa.

[0087] The present invention adds slaked lime (Ca(OH)2) as an auxiliary calcium source, which gradually releases Ca in an alkaline environment. 2+ , synergistically forms a dual cementing network with CaCO3 generated by MICP. The reaction formula is as follows:

[0088] Ca(OH)2+CO3 2- →CaCO3+2OH - .

[0089] The introduction of glutinous rice paste containing amylopectin as a natural adhesive can enhance the bonding force between CaCO3 particles and inhibit the rapid growth of precipitation. 2+ They are combined through coordination bonds to form a denser structure.

[0090] The addition amount of alum (KAl(SO4)2·12H2O) is 0.1-0.3%. 3+ The flocculation effect regulates the crystal morphology of CaCO3, inhibits the formation of irregular crystals, and improves the flexural strength. The reaction formula is as follows:

[0091] Al 3+ +3OH - →Al(OH)3↓

[0092] The generated aluminum hydroxide is adsorbed on the surface of CaCO3.

[0093] Sea sand acts as an inert aggregate, filling micro cracks and providing mechanical support, thus reducing shrinkage stress. The surface hydroxyl groups of the hydrolyzed silica in sea sand can adsorb Ca 2+ , promoting local nucleation. Hydroxyl (-OH) in sea sand (SiO2) belongs to the silanol group (Si-OH) formed by hydrolysis on the surface of silicon dioxide (SiO2). When SiO2 comes into contact with water, some Si-O-Si bonds break, generating silanol groups (Si-OH). The reaction formula is:

[0094] Si-O-Si+H2O→2Si-OH

[0095] Si-OH groups are polar groups that can adsorb Ca in the solution. 2+ , forming a local high calcium concentration area, promoting the nucleation and directional crystallization of CaCO3. In the urea decomposition reaction of Bacillus pasteurianus, Si-OH on the surface of sea sand absorbs Ca 2+ , providing nucleation sites for CaCO3 deposition, thus enhancing the density and flexural strength of cement materials. Silanol groups (Si-OH) adsorb Ca in solution through electrostatic action or ion exchange. 2+ :

[0096] Si-OH+Ca 2+ →Si-O·Ca 2+ +H +

[0097] In this process, the sea sand contains Cl - The following chemical reactions will occur with cement and slaked lime:

[0098] 2(C3S)+6H2O→C3S2H+3Ca(OH)2;

[0099] Ca(OH)2+2Cl - →CaCl2+2OH - ;

[0100] C3A+3CaCl2+32H2O→3CaO·Al2O3·3CaCl2·32H2O;

[0101] C3A+3CaCl2+10H2O→3CaO·Al2O3·CaCl2·10H2O;

[0102] 6Ca 2+ +2[Si(OH)6] 2- +2SO4 2- +2CO3 2-+24H2O→

[0103] Ca6[Si(OH)6]2(SO4) 2- (CO3) 2- 24H2O;

[0104] Ca6[Al(OH)6]2(SO4)3·26H2O+Ca3Si2O7·3H2O+2CaCO3+4H2O+2OH - →Ca6[Si(OH)6]2(SO4)2(CO3)2·24H2O+CaSO4·2H2O+4Ca(OH)2+2Al(OH)4 - ;

[0105] Among them, 3CaO·Al2O3·CaCl2·10H2O and Ca6[Si(OH)6]2(SO4)2(CO3)2·24H2O

[0106] As well as the accompanying formation of ettringite (AFt) and monosulfur type calcium sulfoaluminate (AFm), the strength is formed, and the reaction equation is:

[0107] AFt:C3A+3CSH+26H→C6AS3H 32 ;

[0108] AFm:C6ASH+C3A+4H→4C3ASH 12 ;

[0109] The above reaction can ensure the overall strength of the grouting mortar.

[0110] In a second aspect, the present invention provides a method for preparing a city wall repair grouting material, such as Figure 1 As shown, it includes the following steps:

[0111] S1. Preparation of Bacillus pasteurianus: Bacillus pasteurianus is cultured and acclimated using a five-gradient acclimation method to obtain an acclimated bacterial solution; this step specifically includes the following sub-steps:

[0112] S11. Bacterial expansion: Prepare a basal culture medium containing 10-12 g / L peptone, 3-5 g / L beef extract, and 60-65 g / L urea. Inoculate with Bacillus pasteurianus and place in a constant temperature shaker at 35-40°C and oscillate at 200 rpm.

[0113] S12. Growth monitoring: Use an ultraviolet spectrophotometer (wavelength 600 nm) to dynamically monitor bacterial growth until the OD600 value reaches 0.5-1.0.

[0114] S13. Bacteria collection: Centrifuge the bacterial suspension at 8000×g for 20 minutes, collect the bacterial sludge, wash twice with sterile saline (0.85% NaCl solution), and place in an 80°C water bath for 10-15 minutes. The final bacterial suspension concentration is adjusted to 1×10^8 CFU / mL and stored at -20°C to maintain activity.

[0115] S14, five-gradient acclimation: comprising the following steps: the Bacillus pasteurianus liquid obtained in S23 is continuously passaged at a 1% inoculation rate through five increasing salt concentration gradient culture media, with the gradient concentrations being 4.90±0.5g / L, 9.80±0.5g / L, 14.70±0.5g / L, 19.60±0.5g / L, and 24.53±0.5g / L, respectively; each gradient is cultured until the OD600 is stable and then transferred to the next gradient until the fifth gradient is reached.

[0116] S2, prepare modified shell powder as mixed bacteria carrier, the processing method of modified shell powder comprises the following steps:

[0117] S21. After washing the shells, place them in an oven at 80±2°C, dry them for 4-4.5 hours, and then crush and sieve them to retain shell powder with a particle size of 0.3-0.6 mm;

[0118] S22, immersing the shell powder obtained in S21 in a 30wt% citric acid solution, treating it with ultrasonic immersion for 40 to 60 minutes, and washing it with water until it becomes neutral;

[0119] S23, soaking the shell powder obtained in S22 four times:

[0120] First soaking: Soak in 18-25wt% NaOH solution for 15-30 minutes, then wash with water until neutral;

[0121] Second soaking: Soak in 5-12wt% NaOH solution for 30-40h, then wash with water until neutral;

[0122] Third soaking: soak in 20-30wt% citric acid solution for 2-4 hours, then wash with water until neutral;

[0123] Fourth soaking: soaking in 40-60 wt% NaOH solution for 20-30 hours, washing with water until neutral to obtain shell powder after four soakings;

[0124] S24. Place the shell powder obtained in S23 in an industrial microwave oven and process for 60 minutes, then take it out and cool it to room temperature for later use.

[0125] In a specific embodiment, the shell is a scallop or a mussel, the NaOH is 95% analytically pure solid NaOH powder, and the citric acid is 95% analytically pure solid citric acid powder with a molecular formula of C6H8O7.

[0126] In a specific embodiment of the present application, the initial target weight values of slaked lime, cement, mineral powder, Bacillus pasteurianus solution, and modified shell powder are determined based on the color range of the ancient city wall to be restored, based on the color adjustment model previously constructed. Then, based on the color comparison of the color card to be restored, the target weight values of slaked lime, cement, mineral powder, Bacillus pasteurianus solution, and modified shell powder are fine-tuned to obtain the target weight values of slaked lime, cement, mineral powder, Bacillus pasteurianus solution, and modified shell powder that can match the color of the target ancient city wall. The weight values of the remaining ingredients are then determined based on the weight scores for use in the subsequent blending process.

[0127] S3. Prepare a solidified slurry reaction liquid: add the target weight portion of the acclimated bacterial liquid and the mineralization reaction liquid into a stirring device and stir for 30 to 60 seconds to obtain a solidified slurry reaction liquid. The solidified slurry reaction liquid is divided into a first solidified slurry reaction liquid and a second solidified slurry reaction liquid. The first solidified slurry reaction liquid is used for subsequent grouting material preparation, and the second solidified slurry reaction liquid is used for coating on the surface of the grouting material after grouting.

[0128] S4, dry material premixing: add the target weight amount of slaked lime powder, cement and sea sand into the grouting device and mix and stir; add slaked lime powder, cement, slag, modified shells and sea sand into the grouting device and mix and stir, first stir the dry materials at a low speed (30 r / min) for t4 seconds in the grouting device, then switch to a high speed (60 r / min) and stir for t5 seconds; in this embodiment, t4 is 30 seconds and t5 is 15 seconds.

[0129] S5. Initial mixing: Take 40% of the target weight of water and glutinous rice paste and shake and mix thoroughly in a closed container, then add it to the grouting device and stir for t1 second; in this embodiment, t1 is 30 seconds.

[0130] S6, secondary mixing: 60% of the target weight of water and alum are poured into a closed container for pre-dissolution treatment, and after oscillation and homogenization, they are added to a grouting device and stirred for t2 seconds; in this embodiment, t2 is 45 seconds. The preparation method of glutinous rice slurry is as follows: 30 parts of glutinous rice and 1500 parts of clean water are boiled over high heat, then turned to low heat and cooked until the glutinous rice blooms, and the low heat is continued to cook for 30-35 minutes and then turned off the heat. After it cools naturally, the rice slurry is filtered through a sieve and weighed, and the remaining glutinous rice on the sieve is subsequently rinsed with clean water until the rice slurry reaches 2000 parts, to obtain a glutinous rice slurry with a concentration of 2%.

[0131] S7, biomineralization treatment: slowly add the first solidified slurry reaction liquid obtained in S3 into the grouting device, stir at 2-8°C for t3 seconds, and finally obtain the composite cementitious grouting material. In this embodiment, t3 is 60 seconds.

[0132] In specific applications, Bacillus pasteurianus colonies are usually milky white or light yellow, and urease catalyzes the decomposition of urea to produce carbonate CO3. 2- and ammonium NH4 + , CO3 2- With metal cations in mineral powder such as Ca 2+ Mg 2+ Combining to form carbonate precipitation. In the microbial growth environment of the acid-base modified shell carrier, the dissolution and precipitation of mineral components causes color change. By mixing gray mineral powder with light gray Portland cement in appropriate proportions, the overall hue and alkalinity of the lime mortar can be adjusted. Sulfides in some slag powder react with compounds in Portland cement, primarily producing trace amounts of FeS and MnS hydrated compounds, which appear dark blue. This localized "blue-green variegation" creates a certain aging effect without affecting concrete properties such as strength, low permeability, and durability. Adding an organic microbial slurry reaction solution can alter the surface reflectivity of the particles, allowing for fine-tuning of the color. Alkali control within the slurry causes the salts in the sea sand to react with alkali, creating an aging effect. The externally applied slurry reaction solution acts as a coating, fixing the color, and inhibiting cracking. The synergistic effect of slag, sea sand, cement, and microorganisms on lime achieves color control in the ancient city wall restoration slurry, enhancing the carbon sequestration effect. Specific embodiments

[0134] Low-temperature vortex stirring technology: The temperature is controlled at a low temperature of 2-8°C, the inner wall of the storage barrel is coated with a nano-hydrophobic coating (contact angle > 150°), and a rotating blade (200-800rpm) is used to form a vortex to ensure uniform dispersion of the bacterial solution. The cross-section of the cement stone sample used in the test is rectangular, the sample surface is flat, without bubbles, cracks and other defects, and the size of the test sample is: 160mm×40mm×40mm. The specimens of Examples 1 to 6 were placed in a curing box for 14 days and 28 days and tested for compression and flexural strength. Test specimens 1 and 5 are specimens filled with bacterial solution, and their strength is compared. The unfilled specimens were placed in the bacterial solution reaction solution of Examples 1 and 5, respectively, and then soaked for 28 days and 60 days, respectively, and then tested for strength. Finally, the sample after soaking for 28 days was taken out of the reaction solution, and the specimen cured for 28 days was taken out and its strength was tested.

[0135] The following is a specific example of using microbial slurry to further illustrate the repair effect of using microbial slurry to repair cracks in the ancient Great Wall.

[0136] Table 1 Example slurry mix ratio

[0137]

[0138] Table 2 14-day strength and pH test results of slurry

[0139]

[0140]

[0141] Table 3 28-day strength test results of slurry

[0142] Example Flexural strength (unit: MPa) Compressive strength1(unit:MPa) Compressive strength2(unit: MPa) Example 1 0.71 2.33 2.52 Example 2 0.47 1.41 1.13 Example 3 0.78 2.36 1.82 Example 4 0.38 1.20 1.23 Example 5 0.97 2.24 2.78 Example 6 0.72 1.85 1.63 Comparative Example 0.28 0.65 0.72

[0143] Table 4 180-day strength and pH test results of slurry

[0144] Example Flexural strength (unit: MPa) Compressive strength1(unit:MPa) Compressive strength2(unit: MPa) pH Example 1 0.71 2.33 2.52 9.1 Example 2 0.47 1.41 1.13 8.4 Example 3 0.94 2.82 2.68 8.0 Example 4 0.38 1.20 1.23 8.5 Example 5 0.97 2.24 2.78 8.4 Example 6 1.20 2.79 3.24 8.6 Comparative Example 0.45 0.70 0.75 12.6

[0145] The pH test results at 14, 28, and 180 days show that the examples are generally 2 to 4 times stronger than the conventional repair slurry control. As the slurry age increases to 180 days, the example strength reaches 4.1 times that of the control, demonstrating the excellent reinforcement effect of the slurry mix of the present invention. The test results show that alkalinity steadily decreases with age, with a more pronounced decrease with age, indicating successful alkalinity regulation and a better survival of Bacillus pasteurianus.

[0146] Table 5 Water-bubble microbial slurry strength test

[0147]

[0148] Table 6 28-day strength test results of grouting microbial slurry

[0149] index Traditional MICP slurry Slurry of the present invention (Example 3) Compressive strength (MPa) ≤1.0 2.36 Flexural strength (MPa) ≤0.5 0.78 Slurry uniformity (CV value) 15％ 3％ Nozzle clogging rate 50% (within 1 hour) ≤5% (self-cleaning function)

[0150] It can be seen from Tables 5 and 6 that the strength of the microbial slurry obtained by the on-site cooling grouting method is higher than that of the water-bubble microbial remediation method, which further illustrates the effectiveness of this method. Figure 16 This is a color card comparison chart of the slurry color of the ancient Great Wall of Ming Dynasty, which shows that the slurry of the present invention has the effect of quickly presenting the color of the old site, and can realize the "repairing the old with the old" proposed in the restoration of cultural relics. Figure 15 The repair effects of various examples are also shown. In summary, the present invention solves the problems of low strength and poor uniformity of traditional MICP slurries through the design of a composite gelling system, optimization of anti-interference additives, and dynamic mixing technology. At the same time, through the synergistic effect of sea sand and alum, it achieves a highly efficient enhanced simulation repair of cracks in the ancient city wall.

[0151] In a third aspect, the present invention provides a grouting device for city wall repair grouting material, such as Figures 2 to 13 As shown, it includes a grouting device body 8, a discharge pipe 9 and a grouting support mold. The grouting device body 8 is used to grout the grouting material, and the grouting support mold is used to support the grouting material after grouting to facilitate the repair of the city wall.

[0152] A stirring mechanism 10 is provided on the top of the grouting device body 8, and the stirring mechanism 10 includes a mounting tube 1001, a motor 1002, a movable rod 1003, a first spiral blade 1004, a connecting tube 1005, a funnel 1006, a fixed block 1007 and a movable plate 1008. A mounting tube 1001 is provided on the top of the grouting device body 8, and the motor 1002 is fixedly connected to the inside of the mounting tube 1001, and the output end of the motor 1002 is provided with a movable rod 1003, and the first spiral blade 1004 is provided on the outside of the movable rod 1003. A connecting tube 1005 is fixedly installed on the top of the grouting device body 8, and a funnel 1006 is installed on the top of the connecting tube 1005. A fixed block 1007 is fixedly installed on the inside of the connecting tube 1005, and a movable plate 1008 is hinged on the outside of the fixed block 1007. The two movable plates 1008 are arc-shaped, which can just block the connecting tube 1005 when closed, which is conducive to preventing the slurry from falling.

[0153] In a specific implementation, a disassembly and assembly mechanism 11 is provided on the outside of the grouting device body 8, and the disassembly and assembly mechanism 11 includes an external threaded tube 1101, an internal threaded sleeve 1102, a bellows 1103, a one-way air inlet valve 1104, an inner tube 1105, a rotating rod 1106 and a second threaded blade 1107. The outside of the discharge pipe 9 is fixedly connected with the external threaded tube 1101, the external threaded tube 1101 is provided with an internal threaded sleeve 1102, and the external threaded sleeve 1102 is provided with a bellows. Box 1103, the outside of the bellows 1103 is fixedly connected with a one-way air inlet valve 1104, the inside of the grouting device body 8 is sleeved with an inner tube 1105, the inside of the grouting device body 8 is provided with a rotating rod 1106, and the outside of the rotating rod 1106 is fixedly connected with a second threaded blade 1107. By arranging the internal threaded sleeve 1102 and the external threaded tube 1101, it is convenient to install and disassemble the bellows 1103, which is beneficial to indirect cleaning and prevent the slurry from clogging the grouting device.

[0154] In a specific implementation, a rotating chamber 12 is opened inside the inner tube 1105, and the rotating rod 1106 is located inside the rotating chamber 12. The rotating rod 1106 is three centimeters away from the rotating chamber 12. A shaft seal assembly 13 is set inside the inner tube 1105, and the shaft seal assembly 13 is movably connected to the rotating rod 1106. The setting of the rotating chamber 12 is conducive to the free rotation of the rotating rod 1106. The shaft seal assembly 13 in the present invention is a mechanical seal. The mechanical seal consists of a dynamic ring, a static ring, a sealing ring, a spring, etc. The dynamic ring is pressed against the static ring by liquid pressure and spring force to achieve a sealing effect. Its advantages are good sealing effect, small leakage and long service life, thereby preventing the slurry from leaking from the inner tube 1105 when the rotating rod 1106 is movable.

[0155] In a specific implementation, the external thread of the discharge pipe 9 is connected with a nozzle. There are three types of nozzles, namely a straight pipe head, a flat head and a curved pipe head. By setting up multiple nozzles, it is convenient to install different nozzles according to needs.

[0156] In a specific implementation, the outside of the grouting device body 8 is hinged with a clamping block 14, and the number of the clamping blocks 14 is two. Two first torsion springs 15 are provided on the outside of the grouting device body 8. The two clamping blocks 14 are movably connected to the grouting device body 8 through the two first torsion springs 15 respectively. The torsion spring is a mechanical part that uses elasticity to work and is a type of coil spring. The design principle of the torsion spring is relatively complex and the types vary. The ends of the torsion spring are fixed to other components. When the other components rotate around the center of the spring, the spring pulls them back to the initial position, generating torque or rotational force. The torsion spring can store and release angular energy, or statically fix a device by rotating the force arm around the central axis of the spring body. By providing two first torsion springs 15, the two clamping blocks 14 can be pried apart so that the two first torsion springs 15 are compressed to store energy and clamped on the object through the two clamping blocks 14.

[0157] In a specific implementation, two sliding bars 16 are fixedly installed on the outside of the inner tube 1105, and a sliding groove adapted to the two sliding bars 16 is opened inside the grouting device body 8. The provision of the two sliding bars 16 and the sliding groove facilitates the horizontal sliding of the inner tube 1105.

[0158] In a specific implementation, a block 17 is fixedly installed on the top of the grouting device body 8, and a slot that is compatible with the block 17 is provided at the bottom of the mounting tube 1001. Two screws 18 are provided on the outside of the mounting tube 1001, and the mounting tube 1001 is threadedly connected to the grouting device body 8 through the two screws 18. By providing two screws 18 to be threadedly connected to the grouting device body 8, it is convenient to remove the screws 18 to take out the mounting tube 1001 for repair.

[0159] In a specific implementation, a sealing plate 19 is fixedly installed on the outside of the discharge pipe 9, and two screws 20 are provided on the outside of the sealing plate 19. The sealing plate 19 is threadedly connected to the grouting device body 8 through the two screws 20. By providing two screws 20, it is easy to remove the two screws 20, thereby making it easy to disassemble the sealing plate 19 and the discharge pipe 9.

[0160] In a specific implementation, a second torsion spring 21 is fixedly installed on the outside of the two fixed blocks 1007, and the two second torsion springs 21 are fixedly connected to the two movable plates 1008 respectively. By setting two second torsion springs 21, the slurry can be held by the two second torsion springs 21 and the two movable plates 1008. After the first spiral blade 1004 rotates, the two movable plates 1008 are opened by downward pressure to allow the slurry to flow down.

[0161] In a specific implementation, a feed port 22 is provided at the top of the inner tube 1105 , and the feed port 22 is connected to the bottom of the connecting tube 1005 . Setting the feed port 22 facilitates communication with the bottom of the connecting tube 1005 , thereby facilitating the flow of slurry into the inner tube 1105 .

[0162] In a specific implementation, a control switch 23 is provided on the outside of the mounting tube 1001, and a battery compatible with the control switch 23 is provided on the inside of the mounting tube 1001. The control switch 23 is electrically connected to all electronic components in the present invention through wires, so that all electronic components in the present invention can be controlled by operating the control switch 23.

[0163] The grouting support mold includes a base 101, a main frame 102, a plurality of adjustment plates 103 and a plurality of extension rods 105. The first end of the main frame 102 is fixedly connected to the base 101, and the second end, the third end and the fourth end of the main frame 102 are respectively connected to the adjustment plates 103 by means of the extension rods 105. The first end of the extension rod 105 is telescopically connected to the main frame 102, and the second end of the extension rod 105 is hinged to the adjustment plates 103. The adjustment plates 103 can support the grouting slurry to prevent leakage. The adjustment plates 103 can be adjusted according to the shape of the ancient city wall to ensure that the slurry remains stable during the curing process and prevents it from falling off or deforming. The adjustment plates 103 can also adapt to the complex wall structures of the ancient masonry after wind erosion, such as complex carvings and curved surfaces. The deformable plates can flexibly adapt to these irregular surfaces to ensure that the slurry is evenly distributed.

[0164] The first end of the extension rod 105 is threadedly connected to the second, third, and fourth ends of the main frame 102 and secured with bolts. The second end of the extension rod 105 is hingedly connected to the adjustment plate 103 via a spherical hinge 104 and a semicircular connector 106. The spherical hinge 104 and the semicircular connector 106 work together to adjust the angle and position of the deformable plate to accommodate the complex curved surfaces required for restoration of the ancient city wall.

[0165] The main frame 102 is a cross-shaped frame structure. The main frame 102 and the extension rod 105 are both hollow and have threads inside. Bolts are used for secondary locking when connected to prevent them from falling off.

[0166] The outside of the funnel 1006 is provided with a heat preservation mechanism 24, the outside of the funnel 1006 is fixedly installed with a mounting box 2401, the inside of the mounting box 2401 is fixedly installed with two semiconductor cooling pieces 2402, the inside of the mounting box 2401 is fixedly installed with a temperature sensor 2403, the outside of the mounting box 2401 is fixedly installed with two cooling fans 2404, and the outside of the mounting box 2401 is fixedly installed with a connecting pipe 2405. By setting the heat preservation mechanism 24, the temperature of the funnel can be kept at about 2-8°C, which is beneficial to the biological bacteria inside the slurry. A connecting wire is set inside the connecting pipe 2405, so that the temperature sensor 2403 can be connected to the electronic component point inside the mounting tube 1001, and the external probe of the temperature sensor 2403 is connected to the inside of the funnel 1006, so as to detect the temperature in real time. By setting two semiconductor cooling pieces 2402, the semiconductor cooling piece, also known as the thermoelectric cooler, uses the Peltier effect to achieve cooling, and its core is driven by direct current. Semiconductor materials transfer heat from one side to the other, thereby achieving active cooling, thereby achieving cooling inside the funnel 1006. By setting two cooling fans 2404, the semiconductor refrigeration plate can be dissipated, which is beneficial to cooling. A control switch 23 is provided on the outside of the mounting tube 1001, and a PLC controller electrically connected to the control switch 23 is provided inside the mounting tube 1001. The PLC controller obtains real-time temperature signals through the temperature sensor 2403. After logical operations such as PID control and switch control, the control signal is output to adjust the heating or cooling device so that the temperature is stabilized at the set value, thereby achieving low-temperature control of 2-8°C. The PLC controller in this patent is connected to an external portable external power supply to achieve field work. The control switch 23 can control the start of the PLC controller, thereby adjusting the low temperature according to the real-time temperature signal through the PLC controller to achieve low-temperature control of 2-8°C, which is beneficial for the transportation of microorganisms and slurry stirring to maintain activity. All electronic components in this patent are electrically connected to the PLC controller through wires, and the PLC controller is connected to the controller switch 23 through wire points, so that the PLC controller can be started by the controller switch 23 for automatic low-temperature control.

[0167] Figure 14 For the adaptive fuzzy PID principle diagram, the PLC collects the temperature PV in real time through the temperature sensor, compares it with the set value SV, calculates the deviation and outputs the control signal to adjust the power of the semiconductor refrigeration chip.

[0168] The output control quantity based on the adaptive fuzzy PID control algorithm is:

[0169]

[0170] Where e(k) is the deviation between the temperature setpoint SV and the real-time data acquisition value PV, and e(k-1) is the change in this deviation. The adaptive fuzzy PID controller uses the deviations e(k) and e(k-1) as input signals and uses fuzzy control rules to adjust the PID parameters in real time, achieving better dynamic characteristics.

[0171] During implementation, follow these steps:

[0172] When the ancient city wall needs to be repaired, the grouting material is put into the funnel 1006, and then the installation cylinder 1001 is clamped on the top of the grouting device body 8 through the clamping block 17 and fixed with screws 18 for easy disassembly.

[0173] Then, the small motor 1002 is started by controlling the switch 23, so that the first threaded blade 1004 rotates to stir and mix the slurry, and the rotation speed is accelerated. The slurry generates a downward thrust, pushing the two movable plates 1008 open, allowing the slurry to enter the grouting device body 8, and then the rotating rod 1106 is rotated to rotate and extrude the slurry through the second threaded blade 1107.

[0174] Later, during filling and use, the entire inner tube 1105 is slid outward by cooperating with the sliding bar 16 and the sliding groove, and the external threaded tube 1101 is threadedly connected with the internal threaded sleeve 1102.

[0175] Finally, repeatedly press the bellows 1103 to inflate the interior of the grouting device body 8, which can quickly clean the internal residual material, and then insert the entire inner tube 1105, connect it with the connecting tube 1005 through the feed port 22, and continue to rotate the second threaded blade 1107 to extrude the slurry.

[0176] In summary, the slurry grouting device for repairing the ancient city wall is provided with a stirring mechanism 10. When the ancient city wall needs to be repaired, the raw materials are placed in the funnel 1006, and the mounting tube 1001 is clamped on the top of the grouting device body 8 through the block 17 and fixed with screws 18 for easy disassembly. The small motor 1002 is then started by controlling the switch 23 to rotate the first threaded blade 1004 to stir and mix the slurry. The rotation speed is accelerated, and the slurry generates a downward thrust, pushing the two movable plates 1008 to open, so that the slurry enters the interior of the grouting device body 8. The rotating rod 1106 is then rotated to extrude the slurry through the second threaded blade 1107. The stirring mechanism 10 can directly stir and mix the raw materials, which is convenient for directly repairing the ancient city wall in the field.

[0177] In addition, the grouting device for repairing the ancient city wall is provided with a disassembly and assembly mechanism 11. During filling and use, the sliding bar 16 and the slide groove are cooperated to slide the entire inner tube 1105 outward, and the external threaded tube 1101 is threadedly connected with the internal threaded sleeve 1102. Then, the bellows 1103 is pressed repeatedly to inflate the interior of the grouting device body 8, which can quickly clean up the internal residual material. Then the entire inner tube 1105 is inserted and connected to the connecting tube 1005 through the feed port 22. The second threaded blade 1107 is continued to rotate to squeeze out the slurry. The disassembly and assembly mechanism 11 can blow dust from the inside of the grouting device after use, which is beneficial to improving the service life.

[0178] The above embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A grouting material for repairing an ancient city wall, characterized by: The ingredients included are calculated by weight: 50-60 parts of slaked lime, 15-20 parts of cement, 25-60 parts of mineral powder, 7-9 parts of Bacillus pasteurianus liquid, 10-30 parts of modified shell powder, 30-40 parts of water, 10-15 parts of glutinous rice paste, 1-3 parts of alum, 90-120 parts of sea sand and 7-8 parts of mineralization reaction liquid; The mineralization reaction solution is 0.5 mol / L to 1.0 mol / L calcium chloride solution and 0.5 mol / L to 1.0 mol / L urea solution in a ratio of 1:1, stirred and mixed for 10 to 30 seconds to form a mineralization reaction solution; Using modified shell powder as a mixed bacterial carrier to form an acid-base modified shell carrier microbial growth environment, Bacillus pasteurianus decomposes urea to produce carbonate CO3 through urease catalysis. 2- and ammonium NH4 + , CO3 2- Combined with the metal cations in the mineral powder to form carbonate precipitation; in the microbial growth environment of the acid-base modified shell carrier, the mineral components dissolve and precipitate, causing color changes. By adjusting the weight ratio of slaked lime, cement, mineral powder, Bacillus pasteurianus liquid and modified shell powder, the color depth of the grouting material can be adjusted. The color adjustment model is as follows: Wherein, C is the change in the color of the grouting material, C0 is the basic color value of the grouting material, a, b, c, d, e are the target adjustment weight portions of slaked lime, cement, mineral powder, Bacillus pasteurianus solution and modified shell powder respectively, and the value ranges of a, b, c, d, e are: a∈[50,60], b∈[15,20], c∈[25,60], d∈[7,9], e∈[10,30] respectively; a0, b0, c0, d0, e0 are the basic weight portions of slaked lime, cement, mineral powder, Bacillus pasteurianus solution and modified shell powder respectively, and k a 、k b 、k c 、k d 、k e They are the proportion adjustment coefficients of slaked lime, cement, mineral powder, Bacillus pasteurianus liquid and modified shell powder.

2. The ancient city wall repair grouting material according to claim 1, characterized in that: The pH value of the Bacillus pasteurianus liquid is 8.0-9.2, the slaked lime is slaked lime with a calcium content of 95%, the alum is edible alum powder with a particle size of 50-150 microns, the slag is S95 grade with a sulfur content of 3.5-4%, the chloride ion content of the sea sand is 0.03%-0.06% by mass, the particle size is 0.15mm-2.36mm, the fineness modulus is 2.3-3.0, the pH value is 7.0-7.5, and the cement is P﹒O42.5 cement.

3. The ancient city wall repair grouting material according to claim 2, characterized in that: The values of a0, b0, c0, d0, and e0 are 60, 15, 45, 8, and 20 respectively. a 、k b 、k c 、k d 、k e The values of are fitted by the least squares method, and the values after fitting are 0.3, 0.6, 0.8, 1, and 0.6 respectively.

4. A method for preparing the grouting material for repairing the ancient city wall according to claim 1, characterized in that: It includes the following steps: S1. Preparing Bacillus pasteurianus: expanding the culture of Bacillus pasteurianus and acclimating the Bacillus pasteurianus using a five-gradient acclimation method to obtain an acclimated bacterial liquid; S2, preparing modified shell powder as a mixed bacteria carrier; S3. Preparing a solidified slurry reaction liquid: adding the acclimated bacterial liquid and the mineralization reaction liquid to a stirring device according to a target weight ratio and stirring for 30 to 60 seconds to obtain a solidified slurry reaction liquid. The solidified slurry reaction liquid is divided into a first solidified slurry reaction liquid and a second solidified slurry reaction liquid. The first solidified slurry reaction liquid is used for subsequent grouting material preparation, and the second solidified slurry reaction liquid is used for coating the surface of the grouting material after grouting. S4. Dry material premixing: adding slaked lime powder, cement, slag, modified shell powder and sea sand to the grouting device according to the target weight ratio and mixing and stirring; S5, initial mixing: take 40% of the target weight of water and glutinous rice paste in a closed container and shake and mix thoroughly, then add it to the grouting device and stir for t1 second; S6, secondary mixing: take 60% of the target weight of water and alum into a sealed container for pre-dissolution, shake and homogenize, add to the grouting device and stir for 2 seconds; S7. Biomineralization treatment: slowly add the first solidified slurry reaction liquid prepared in S3 into the grouting device, stir at 2-8° C. for 3 seconds, and finally obtain the composite cementitious material grouting material.

5. The method for preparing the ancient city wall repair grouting material according to claim 4, characterized in that: S1 specifically includes the following sub-steps: S11. Bacterial expansion: Prepare a basal medium containing 10-12 g / L peptone, 3-5 g / L beef extract, and 60-65 g / L urea, inoculate with Bacillus pasteurianus, and place in a constant temperature shaker at 35-40°C and shake at 200-220 rpm; S12. Growth monitoring: Use an ultraviolet spectrophotometer to dynamically monitor bacterial growth until the OD600 value reaches 0.5-1.0; S13. Bacteria collection: centrifuge the bacterial suspension, collect the bacterial sludge, wash it with sterile saline, and place it in an 80°C water bath for 10-15 min. The final bacterial suspension concentration is adjusted to 1×10^8 CFU / mL and stored at -20°C to maintain activity. S14. Five-gradient acclimation: The Bacillus pasteurianus culture liquid was serially passaged at a 1% inoculum size through five increasing salt concentration gradient media, with the gradient concentrations being 4.90±0.5g / L, 9.80±0.5g / L, 14.70±0.5g / L, 19.60±0.5g / L, and 24.53±0.5g / L, respectively; each gradient name was cultured until the OD600 was stable and then transferred to the next gradient until the five gradients were completed.

6. The method for preparing the ancient city wall repair grouting material according to claim 4, characterized in that: In the S4 dry material premix, slaked lime powder, cement, slag, modified shell powder and sea sand are added to the grouting device and stirred at 30r / min for 4 seconds to mix the dry materials, and then stirred at 60r / min for 5 seconds. <t2<t3,t2=1.5t1,t3=1.5t2,t4=2t5。 7. The method for preparing the ancient city wall repair grouting material according to claim 4, characterized in that: S2 specifically includes the following sub-steps: S21, after washing the shells, placing them in an oven at a temperature of 80±2°C, drying them for 4-4.5 hours, and then crushing and sieving them to retain shell powder with a particle size of 0.3-0.6 mm; S22, immersing the shell powder obtained in S21 in a 30wt% citric acid solution, treating it with ultrasonic immersion for 40 to 60 minutes, and washing it with water until it becomes neutral; S23, soaking the shell powder obtained in S22 four times: First soaking: Soak in 18-25wt% NaOH solution for 15-30 minutes, then wash with water until neutral; Second soaking: Soak in 5-12wt% NaOH solution for 30-40h, then wash with water until neutral; Third soaking: soak in 20-30wt% citric acid solution for 2-4 hours, then wash with water until neutral; Fourth soaking: soaking in 40-60 wt% NaOH solution for 20-30 hours, washing with water until neutral to obtain shell powder after four soakings; S24. Place the shell powder obtained in S23 in an industrial microwave oven and process for 60 minutes, then take it out and cool it to room temperature for later use.

8. A grouting device for repairing grouting material for ancient city walls, characterized by: It includes a grouting device body, a discharge pipe and a grouting support mold, and a stirring mechanism is provided on the top of the grouting device body; The stirring mechanism includes a mounting tube, a motor, a movable rod, a first spiral blade, a connecting tube, a funnel, a fixed block and a movable plate. The connecting tube and the mounting tube are arranged on the top of the grouting device body, the motor is arranged inside the mounting tube, the output end of the motor is provided with a movable rod, the outside of the movable rod is provided with a first spiral blade, the top of the connecting tube is provided with a funnel, the inside of the connecting tube is fixedly provided with a fixed block, and the outside of the fixed block is hinged with a movable plate; a cooling mechanism is provided on the outside of the stirring mechanism, and the cooling mechanism is connected to a PLC controller. The PLC controller obtains real-time temperature signals through a temperature sensor and outputs control signals to the cooling mechanism after logical operation; The grouting support mold includes a base, a main frame, multiple adjustment plates and multiple extension rods. The first end of the main frame is fixedly connected to the base, and the second end, the third end and the fourth end of the main frame are respectively connected to the adjustment plates by means of extension rods. The first end of the extension rod can be telescopically connected to the main frame, and the second end of the extension rod is hinged to the adjustment plate.

9. The grouting device for the ancient city wall repair grouting material according to claim 8, characterized in that: The outside of the grouting device body is provided with a disassembly and assembly mechanism, including an external threaded tube, an internal threaded sleeve, a bellows, a one-way air inlet valve, an inner tube, a rotating rod and a second threaded blade. The outside of the discharge pipe is fixedly connected with the external threaded tube, the outside of the external threaded tube is provided with an internal threaded sleeve, the outside of the internal threaded sleeve is provided with a bellows, the outside of the bellows is fixedly connected with the one-way air inlet valve, the interior of the grouting device body is sleeved with the inner tube, the interior of the grouting device body is provided with a rotating rod, and the outside of the rotating rod is fixedly connected with the second threaded blade; a rotating cavity is opened inside the inner tube, the rotating rod is located inside the rotating cavity and has a gap with the rotating cavity, a shaft sealing assembly is set inside the inner tube, the shaft sealing assembly is movably connected to the rotating rod, two sliding bars are fixedly installed on the outside of the inner tube, a sliding groove adapted to the two sliding bars is opened inside the grouting device body, and a clamping block is hinged on the outside of the grouting device body, and the clamping block is movably connected to the grouting device body by means of a first torsion spring. A feed port is provided at the top of the inner tube, and the feed port is connected to the bottom of the connecting tube.

10. The grouting device for the ancient city wall repair grouting material according to claim 8, characterized in that: The heat preservation mechanism includes an installation box, a semiconductor refrigeration sheet, a temperature sensor and a heat dissipation fan. The interior of the installation box is fixedly installed with a semiconductor refrigeration sheet, the interior of the installation box is fixedly installed with a temperature sensor, the exterior of the installation box is fixedly installed with a heat dissipation fan and a connecting pipe, and the output end of the PLC controller is connected to the input end of the semiconductor refrigeration sheet; The PLC controller collects the temperature PV in real time through the temperature sensor, compares it with the set value SV, calculates the deviation and outputs a control signal to adjust the power of the semiconductor refrigeration chip.

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