A concrete microbial corrosion simulation device and a microbial corrosion simulation method under a marine environment

Abstract

The application discloses a concrete microbial corrosion simulation device and a microbial corrosion simulation method in a marine environment, and relates to a concrete microbial corrosion simulation device and a simulation method. In order to solve the problem that the existing microbial corrosion of concrete can only simulate a single corrosion zone and only select a single acid-producing microorganism for simulation, so that the simulation result is inaccurate, the device realizes laboratory in-situ simulation of three typical microbial corrosion regions, namely, a marine environment atmospheric zone, a tidal range zone and a full immersion zone, has good simulation effect and high automation degree. The application adopts a synergistic corrosion microbial corrosion concrete experiment method, provides a solution for a subsequent experiment method for exploring the action and mechanism of the synergistic acid-producing microorganisms in different corrosion zones of the concrete in the marine environment, and is more in line with the actual situation, and is favorable for subsequent research on the mechanism of the microbial corrosion of the concrete.

Description

Technical Field

[0001] This invention relates to a device and method for simulating microbial corrosion of concrete. Background Technology

[0002] Concrete, as a low-cost engineering construction material, is widely used in various marine infrastructures. However, the high temperature and humidity of the marine environment accelerates the corrosion of concrete structures, often resulting in a shorter-than-expected service life for infrastructure in the region, significantly increasing its life-cycle cost. Researchers have found that the corrosive effect of marine synergistic acid-producing microorganisms on concrete is one of the important reasons for the reduced service life of concrete infrastructure. Furthermore, marine corrosion zones are divided into the marine atmospheric zone, the splash zone, the tidal zone, the fully submerged seawater zone, and the seabed mud zone. The different growth and metabolic rates of microorganisms in these zones lead to different corrosion rates on the concrete in their respective zones. To further investigate the corrosive effects and mechanisms of synergistic acid-producing microorganisms on concrete in different corrosion zones, it is urgent to develop corresponding simulation devices and methods for microbial corrosion of concrete in marine environments.

[0003] For example, patents such as "Experimental Device and Method for Microbial Corrosion of Concrete under Simulated Seawater Environment", "Comprehensive Simulation System for Marine Tidal Salt Fog Environment", and "Durability Experimental Device for Simulating Marine Tidal Effect in Artificial Environment" can only simulate a single corrosion zone. Both "Comprehensive Simulation System for Marine Tidal Salt Fog Environment" and "Durability Experimental Device for Simulating Marine Tidal Effect in Artificial Environment" require a control system to operate the device. Patents "Experimental Device and Method for Microbial Corrosion of Concrete under Simulated Seawater Environment" and "Experimental Device and Method for Microbial Corrosion of Concrete under Simulated Seawater Environment" only select a single acid-producing microorganism, which limits the research on corrosion mechanism. Summary of the Invention

[0004] To address the problem that existing methods for simulating microbial corrosion of concrete can only simulate a single corrosion zone and that selecting only a single acid-producing microorganism results in inaccurate simulations, this invention proposes a device and method for simulating microbial corrosion of concrete in a marine environment.

[0005] The present invention provides a marine environment-based concrete microbial corrosion simulation device consisting of a bacterial seawater chamber (1), a corrosion reaction chamber (2), and a waste gas treatment chamber (3). The corrosion reaction chamber (2) is equipped with a mixer (5), an atomizing nozzle (6), a heater (12), and a stainless steel sample holder. The outer side wall of the corrosion reaction chamber (2) has a sampling port (15) and a spray liquid outlet. The atomizing nozzle (6) is connected to the spray liquid outlet via a spray pipe (13), and a pressure pump (14) is installed on the spray pipe (13). The atomizing nozzle (6) is located at the top of the corrosion reaction chamber (2), and the heater (12)... The stainless steel sample holder is composed of multiple partitions and is located at the bottom of the corrosion reaction chamber (2). A first gas pipe (25) and a second gas pipe (17) are symmetrically arranged on the upper part of the corrosion reaction chamber (2). The outlet of the first gas pipe (25) is connected to the inlet of the corrosion reaction chamber (2), and the inlet of the first gas pipe (25) is connected to the atmosphere. A first vacuum pump (24), a first gas solenoid valve (26), and a first gas check valve (27) are arranged sequentially on the first gas pipe (25). The first vacuum pump (24) is located on one side of the inlet of the first gas pipe (25). The inlet of the pipeline (17) is connected to the outlet of the corrosion reaction chamber (2), and the outlet of the second gas pipeline (17) is connected to the inlet of the waste gas treatment chamber (3); a second vacuum pump (16), a second gas solenoid valve (18), and a second gas check valve (19) are sequentially installed on the second gas pipeline (17); the second vacuum pump (16) is located on one side of the inlet of the second gas pipeline (17); the upper part of the corrosion reaction chamber (2) is connected to the upper part of the bacteria-containing seawater chamber (1) through a gas connecting pipe (7); the lower part of the corrosion reaction chamber (2) is connected to the lower part of the bacteria-containing seawater chamber (1) through a first liquid pipeline (1). 1) Connected to the second liquid pipeline (23); the first liquid pipeline (11) is sequentially equipped with a first liquid check valve (8), a first liquid solenoid valve (9) and a first peristaltic pump (10), the first peristaltic pump (10) is located on one side of the corrosion reaction chamber (2); the second liquid pipeline (23) is sequentially equipped with a second peristaltic pump (20), a second liquid solenoid valve (21) and a second liquid check valve (22), the second peristaltic pump (20) is located on one side of the bacteria-containing seawater chamber (1), the bacteria-containing seawater chamber (1) stores seawater containing acid-producing microorganisms; the acid-producing microorganisms are Staphylococcus and Thiobacillus.

[0006] The present invention utilizes a concrete microbial corrosion simulation device in a marine environment to simulate microbial corrosion, and the method for simulating microbial corrosion follows these steps:

[0007] I. Preparation of concrete specimens

[0008] (1) Weigh the raw materials according to the designed concrete specimen mix proportion. The raw materials are coarse aggregate, fine aggregate, mineral powder, fly ash, ordinary Portland cement, water, water-reducing agent and defoamer. Add the coarse aggregate, fine aggregate, mineral powder, fly ash and ordinary Portland cement to the horizontal twin-shaft mixer in sequence for dry mixing. The time interval between adding each raw material is 60 seconds. Mix the water, water-reducing agent and defoamer and add them evenly to the mixer. Then mix for 5 minutes until the mixture is uniform and has good fluidity.

[0009] (2) Pour the mixed concrete into a mold coated with release agent in one go, and place it on a vibrating table to vibrate for 2 minutes;

[0010] (3) Curing was carried out to obtain multiple concrete specimens;

[0011] 2. Weigh the concrete specimens using an electronic precision balance and perform a dynamic elastic modulus test before corrosion.

[0012] III. Microbial Corrosion Simulation of Concrete

[0013] (1) The seawater tank (1) containing bacteria is divided into atmospheric zone, tidal zone and full immersion zone according to the height from top to bottom; multiple concrete specimens are placed on stainless steel sample holders at different heights in the atmospheric zone, tidal zone and full immersion zone of the seawater tank (1) containing bacteria.

[0014] (2) Store seawater containing acid-producing microorganisms in the bacteria-containing seawater tank (1) and adjust the water level of the corrosion reaction tank (2) to the bottom height of the tidal zone; use the heater (12) to control and maintain the temperature inside the corrosion reaction tank (2) at the set temperature; use the mixer (5) to stir the seawater containing acid-producing microorganisms, and start the mixer (5) twice a day for 2 hours each time and stop for 10 hours each time; use the atomizing nozzle (6) to spray the seawater containing acid-producing microorganisms in the corrosion reaction tank (2) to the atmospheric zone and the tidal zone, and maintain the humidity of the atmospheric zone and the tidal zone at 100%RH;

[0015] (3) The tidal process is simulated by draining water through the first peristaltic pump (10) and supplying water through the second peristaltic pump (20). The tidal process includes the following cycle: the seawater level drops from the top of the tidal zone to the bottom of the tidal zone, the seawater level remains at the bottom of the tidal zone for a period of time, the seawater level rises from the bottom of the tidal zone to the top of the tidal zone, and the seawater level remains at the top of the tidal zone for a period of time. During this period, the seawater containing acid-producing microorganisms is renewed every 15 days. At the same time, air is drawn from the atmosphere and sent into the corrosion reaction chamber (2) through the first vacuum pump (24), and hydrogen sulfide gas is extracted through the second vacuum pump (16) to ensure that the oxygen concentration in the chamber is maintained at 18-20.5% and the O2 volume concentration is controlled at 18-20.5%. The hydrogen sulfide gas is adsorbed and removed in the waste gas treatment chamber (3).

[0016] 4. Take out the concrete specimens that have been simulated in step 3 (atmospheric zone, tidal zone, and total immersion zone), separate the biofilm on the surface of the concrete specimens, and conduct biofilm thickness test and biofilm surface staining test for live and dead bacteria.

[0017] 5. After cleaning the biofilm off the surface of the concrete specimens, place them indoors to dry, then weigh them and perform tests on the dynamic elastic modulus, flexural strength, compressive strength, XRD, and porosity after corrosion.

[0018] The effects of this invention are:

[0019] In the corrosion reaction chamber (2) of the marine environment concrete microbial corrosion simulation device of the present invention, acid-producing microorganisms in the seawater produce hydrogen sulfide gas. When the oxygen concentration in the corrosion reaction chamber (2) is too low, air is drawn from the atmosphere and sent into the corrosion reaction chamber (2) by the first vacuum pump (24), and hydrogen sulfide gas is extracted by the second vacuum pump (16) to ensure the stability of the oxygen concentration in the chamber. At the same time, the hydrogen sulfide gas is adsorbed and removed in the waste gas treatment chamber (3), thereby ensuring the safety of the experimental personnel and the green and safe operation of the device. The water level in the corrosion reaction chamber (2) is adjusted by draining water with the first peristaltic pump (10) and supplying water with the second peristaltic pump (20). At the same time, the tidal process is simulated by draining water with the first peristaltic pump (10) and supplying water with the second peristaltic pump (20). The tidal process includes the following cycle: the seawater level drops from the top of the tidal zone to the bottom of the tidal zone, the seawater level remains at the bottom of the tidal zone for a period of time, the seawater level rises from the bottom of the tidal zone to the top of the tidal zone, and the seawater level remains at the top of the tidal zone for a period of time. The atomizing nozzle (6) sprays the seawater containing acid-producing microorganisms in the corrosion reaction chamber (2) into the atmospheric zone and the tidal zone, maintaining the humidity of the atmospheric zone and the tidal zone at 100%RH, and adding bacteria to the test specimen. The sampling port (15) is used to take water samples or drain water. The stainless steel sample holder is composed of multiple partitions, which facilitates the placement of concrete specimens. The heater (12) is used to maintain a constant temperature inside the corrosion reaction chamber (2); the upper part of the corrosion reaction chamber (2) is connected to the upper part of the bacteria-containing seawater chamber (1) through a gas connecting pipe (7) to ensure that the gas pressure inside the corrosion reaction chamber (2) and the bacteria-containing seawater chamber (1) is consistent.

[0020] The device of this invention enables in-situ laboratory simulation of three typical microbial corrosion zones in the marine environment: atmospheric zone, tidal zone, and total immersion zone. It features good simulation effect, high degree of automation, ease of operation, and strong safety.

[0021] This invention presents an experimental method for the synergistic corrosion of concrete by microorganisms, providing a solution for subsequent experimental studies on the effects and mechanisms of synergistic acid-producing microorganisms on concrete corrosion in different corrosion zones under marine environments. The invention selects two synergistic acid-producing microorganisms, which is more consistent with reality, as microbial corrosion of concrete is often caused by synergistic acid-producing microorganisms, facilitating subsequent research on the mechanisms of microbial corrosion of concrete. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the concrete microbial corrosion simulation device in a marine environment in Example 1;

[0023] Figure 2 This is a schematic diagram of the testing process of the test specimen inside the corrosion reaction chamber (2); in the figure, a is the stainless steel sample holder and b is the concrete specimen to be tested;

[0024] Figure 3 The XRD pattern of the fully immersed specimen before microbial corrosion is shown.

[0025] Figure 4 The XRD pattern of the fully immersed specimen after 150 days of microbial corrosion.

[0026] Figure 5 This is a diagram showing the distribution of live and dead bacteria staining in the biofilm of the specimen in the tidal zone after 150 days of corrosion.

[0027] Figure 6 This is a diagram showing the distribution of live and dead bacteria staining in the biofilm of the specimen in the fully immersed zone after 150 days of corrosion. Detailed Implementation

[0028] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any reasonable combination of the specific embodiments.

[0029] Specific Implementation Method 1: This implementation method for simulating microbial corrosion of concrete in a marine environment consists of a seawater tank containing bacteria (1), a corrosion reaction tank (2), and a waste gas treatment tank (3). The corrosion reaction tank (2) is equipped with a mixer (5), an atomizing nozzle (6), a heater (12), and a stainless steel sample holder. The outer side wall of the corrosion reaction tank (2) is provided with a sampling port (15) and a spray liquid outlet. The atomizing nozzle (6) is connected to the spray liquid outlet through a spray pipe (13), and a pressure pump (14) is provided on the spray pipe (13). The atomizing nozzle (6) is located at the top inside the corrosion reaction tank (2), and the heater (12) is located at the top. The stainless steel sample holder is composed of multiple partitions and is located at the bottom of the corrosion reaction chamber (2). The upper part of the corrosion reaction chamber (2) is symmetrically equipped with a first gas pipe (25) and a second gas pipe (17). The outlet of the first gas pipe (25) is connected to the inlet of the corrosion reaction chamber (2), and the inlet of the first gas pipe (25) is connected to the atmosphere. The first gas pipe (25) is equipped with a first vacuum pump (24), a first gas solenoid valve (26), and a first gas check valve (27) in sequence. The first vacuum pump (24) is located on one side of the inlet of the first gas pipe (25). The inlet end of the body pipe (17) is connected to the outlet of the corrosion reaction chamber (2), and the outlet end of the second gas pipe (17) is connected to the inlet of the waste gas treatment chamber (3); a second vacuum pump (16), a second gas solenoid valve (18), and a second gas check valve (19) are sequentially installed on the second gas pipe (17); the second vacuum pump (16) is located on one side of the inlet end of the second gas pipe (17); the upper part of the corrosion reaction chamber (2) is connected to the upper part of the bacteria-containing seawater chamber (1) through a gas connecting pipe (7); the lower part of the corrosion reaction chamber (2) is connected to the lower part of the bacteria-containing seawater chamber (1) through a first liquid pipe ( 11) Connected to the second liquid pipeline (23); the first liquid pipeline (11) is sequentially provided with a first liquid check valve (8), a first liquid solenoid valve (9) and a first peristaltic pump (10), the first peristaltic pump (10) is located on one side of the corrosion reaction chamber (2); the second liquid pipeline (23) is sequentially provided with a second peristaltic pump (20), a second liquid solenoid valve (21) and a second liquid check valve (22), the second peristaltic pump (20) is located on one side of the bacteria-containing seawater chamber (1), the bacteria-containing seawater chamber (1) stores seawater containing acid-producing microorganisms; the acid-producing microorganisms are Staphylococcus and Thiobacillus.

[0030] In this embodiment, the acid-producing microorganisms in the seawater containing the acid-producing microorganisms in the corrosion reaction chamber (2) of the concrete microbial corrosion simulation device in a marine environment produce hydrogen sulfide gas. When the oxygen concentration in the corrosion reaction chamber (2) is too low, air is drawn from the atmosphere and sent into the corrosion reaction chamber (2) by the first vacuum pump (24), and hydrogen sulfide gas is extracted by the second vacuum pump (16) to ensure the stability of the oxygen concentration in the chamber. At the same time, the hydrogen sulfide gas is adsorbed and removed in the waste gas treatment chamber (3), thereby ensuring the safety of the experimental personnel and the green and safe operation of the device. The water level in the corrosion reaction chamber (2) is adjusted by draining water with the first peristaltic pump (10) and supplying water with the second peristaltic pump (20). At the same time, the tidal process is simulated by draining water with the first peristaltic pump (10) and supplying water with the second peristaltic pump (20). The tidal process includes the following cycle: the seawater level drops from the top of the tidal zone to the bottom of the tidal zone, the seawater level remains at the bottom of the tidal zone for a period of time, the seawater level rises from the bottom of the tidal zone to the top of the tidal zone, and the seawater level remains at the top of the tidal zone for a period of time. The atomizing nozzle (6) sprays the seawater containing acid-producing microorganisms in the corrosion reaction chamber (2) into the atmospheric zone and the tidal zone, maintaining the humidity of the atmospheric zone and the tidal zone at 100%RH, and adding bacteria to the test specimen. The sampling port (15) is used to take water samples or drain water. The stainless steel sample holder is composed of multiple partitions, which facilitates the placement of concrete specimens. The heater (12) is used to maintain a constant temperature inside the corrosion reaction chamber (2); the upper part of the corrosion reaction chamber (2) is connected to the upper part of the bacteria-containing seawater chamber (1) through a gas connecting pipe (7) to ensure that the gas pressure inside the corrosion reaction chamber (2) and the bacteria-containing seawater chamber (1) is consistent.

[0031] The device described in this embodiment enables in-situ laboratory simulation of three typical microbial corrosion zones in the marine environment: atmospheric zone, tidal zone, and total immersion zone. It features good simulation effect, high degree of automation, ease of operation, and strong safety.

[0032] This embodiment presents an experimental method for the synergistic corrosion of concrete by microorganisms, providing a solution for subsequent experimental methods to investigate the effects and mechanisms of synergistic acid-producing microorganisms on concrete corrosion in different corrosion zones under marine environments. This embodiment selects two synergistic acid-producing microorganisms, which is more consistent with reality, as microbial corrosion of concrete is often caused by synergistic acid-producing microorganisms, facilitating subsequent research on the mechanisms of microbial corrosion of concrete.

[0033] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the material of the bacteria-containing seawater tank (1) is PE.

[0034] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 in that the waste gas treatment chamber (3) is filled with hydrogen sulfide adsorption material.

[0035] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the hydrogen sulfide adsorbent material is activated carbon, zinc oxide, or iron oxide.

[0036] Specific Implementation Method Five: This implementation method utilizes a concrete microbial corrosion simulation device in a marine environment to simulate microbial corrosion, following these steps:

[0037] I. Preparation of concrete specimens

[0038] (1) Weigh the raw materials according to the designed concrete specimen mix proportion. The raw materials are coarse aggregate, fine aggregate, mineral powder, fly ash, ordinary Portland cement, water, water-reducing agent and defoamer. Add the coarse aggregate, fine aggregate, mineral powder, fly ash and ordinary Portland cement to the horizontal twin-shaft mixer in sequence for dry mixing. The time interval between adding each raw material is 60 seconds. Mix the water, water-reducing agent and defoamer and add them evenly to the mixer. Then mix for 5 minutes until the mixture is uniform and has good fluidity.

[0039] (2) Pour the mixed concrete into a mold coated with release agent in one go, and place it on a vibrating table to vibrate for 2 minutes;

[0040] (3) Curing was carried out to obtain multiple concrete specimens;

[0041] 2. Weigh the concrete specimens using an electronic precision balance and perform a dynamic elastic modulus test before corrosion.

[0042] III. Microbial Corrosion Simulation of Concrete

[0043] (1) The seawater tank (1) containing bacteria is divided into atmospheric zone, tidal zone and full immersion zone according to the height from top to bottom; multiple concrete specimens are placed on stainless steel sample holders at different heights in the atmospheric zone, tidal zone and full immersion zone of the seawater tank (1) containing bacteria.

[0044] (2) Store seawater containing acid-producing microorganisms in the bacteria-containing seawater tank (1) and adjust the water level of the corrosion reaction tank (2) to the bottom height of the tidal zone; use the heater (12) to control and maintain the temperature inside the corrosion reaction tank (2) at the set temperature; use the mixer (5) to stir the seawater containing acid-producing microorganisms, and start the mixer (5) twice a day for 2 hours each time and stop for 10 hours each time; use the atomizing nozzle (6) to spray the seawater containing acid-producing microorganisms in the corrosion reaction tank (2) to the atmospheric zone and the tidal zone, and maintain the humidity of the atmospheric zone and the tidal zone at 100%RH;

[0045] (3) The tidal process is simulated by draining water through the first peristaltic pump (10) and supplying water through the second peristaltic pump (20). The tidal process includes the following cycle: the seawater level drops from the top of the tidal zone to the bottom of the tidal zone, the seawater level remains at the bottom of the tidal zone for a period of time, the seawater level rises from the bottom of the tidal zone to the top of the tidal zone, and the seawater level remains at the top of the tidal zone for a period of time. During this period, the seawater containing acid-producing microorganisms is renewed every 15 days. At the same time, air is drawn from the atmosphere and sent into the corrosion reaction chamber (2) through the first vacuum pump (24), and hydrogen sulfide gas is extracted through the second vacuum pump (16) to ensure that the oxygen concentration in the chamber is maintained at 18-20.5% and the O2 volume concentration is controlled at 18-20.5%. The hydrogen sulfide gas is adsorbed and removed in the waste gas treatment chamber (3).

[0046] 4. Take out the concrete specimens that have been simulated in step 3 (atmospheric zone, tidal zone, and total immersion zone), separate the biofilm on the surface of the concrete specimens, and conduct biofilm thickness test and biofilm surface staining test for live and dead bacteria.

[0047] 5. After cleaning the biofilm off the surface of the concrete specimens, place them indoors to dry, then weigh them and perform tests on the dynamic elastic modulus, flexural strength, compressive strength, XRD, and porosity after corrosion.

[0048] In this embodiment, the acid-producing microorganisms in the seawater containing the acid-producing microorganisms in the corrosion reaction chamber (2) of the concrete microbial corrosion simulation device in a marine environment produce hydrogen sulfide gas. When the oxygen concentration in the corrosion reaction chamber (2) is too low, air is drawn from the atmosphere and sent into the corrosion reaction chamber (2) by the first vacuum pump (24), and hydrogen sulfide gas is extracted by the second vacuum pump (16) to ensure the stability of the oxygen concentration in the chamber. At the same time, the hydrogen sulfide gas is adsorbed and removed in the waste gas treatment chamber (3), thereby ensuring the safety of the experimental personnel and the green and safe operation of the device. The water level in the corrosion reaction chamber (2) is adjusted by draining water with the first peristaltic pump (10) and supplying water with the second peristaltic pump (20). At the same time, the tidal process is simulated by draining water with the first peristaltic pump (10) and supplying water with the second peristaltic pump (20). The tidal process includes the following cycle: the seawater level drops from the top of the tidal zone to the bottom of the tidal zone, the seawater level remains at the bottom of the tidal zone for a period of time, the seawater level rises from the bottom of the tidal zone to the top of the tidal zone, and the seawater level remains at the top of the tidal zone for a period of time. The atomizing nozzle (6) sprays the seawater containing acid-producing microorganisms in the corrosion reaction chamber (2) into the atmospheric zone and the tidal zone, maintaining the humidity of the atmospheric zone and the tidal zone at 100%RH, and adding bacteria to the test specimen. The sampling port (15) is used to take water samples or drain water. The stainless steel sample holder is composed of multiple partitions, which facilitates the placement of concrete specimens. The heater (12) is used to maintain a constant temperature inside the corrosion reaction chamber (2); the upper part of the corrosion reaction chamber (2) is connected to the upper part of the bacteria-containing seawater chamber (1) through a gas connecting pipe (7) to ensure that the gas pressure inside the corrosion reaction chamber (2) and the bacteria-containing seawater chamber (1) is consistent.

[0049] The device described in this embodiment enables in-situ laboratory simulation of three typical microbial corrosion zones in the marine environment: atmospheric zone, tidal zone, and total immersion zone. It features good simulation effect, high degree of automation, ease of operation, and strong safety.

[0050] This embodiment presents an experimental method for the synergistic corrosion of concrete by microorganisms, providing a solution for subsequent experimental methods to investigate the effects and mechanisms of synergistic acid-producing microorganisms on concrete corrosion in different corrosion zones under marine environments. This embodiment selects two synergistic acid-producing microorganisms, which is more consistent with reality, as microbial corrosion of concrete is often caused by synergistic acid-producing microorganisms, facilitating subsequent research on the mechanisms of microbial corrosion of concrete.

[0051] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method Five in that: the mix ratio of the concrete specimen in step one (1) is: by mass ratio, ordinary Portland cement: fine aggregate: coarse aggregate: mineral powder: fly ash: water: water-reducing agent: defoamer = 170-370: 750-900: 1100-1300: 50-150: 50-150: 80-90: 0.6-1.2: 0.01-0.2.

[0052] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Five in that: the total immersion zone in step three (1) is between 0 and 50 cm in height inside the bacteria-containing seawater tank (1), the tidal zone is between 50 and 100 cm in height inside the bacteria-containing seawater tank (1), and the atmospheric zone is between 100 cm and 150 cm inside the bacteria-containing seawater tank (1).

[0053] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Five in that: the preparation method of the seawater containing acid-producing microorganisms in step three (1) is as follows: First, prepare 160L of artificial seawater, then mix 1600g of Thiobacillus culture medium and 1600g of Staphylococcus culture medium evenly and add them to the artificially prepared seawater, irradiate with ultraviolet light for 12 hours, and then add 400mL of a concentration of 2.98×10 8 CFU / mL Thiobacillus bacterial suspension and 400 mL of 3.06×10⁻⁶ CFU / mL Thiobacillus bacterial suspension 8 The staphylococcal culture solution at CFU / mL showed that both Thiobacillus and Staphylococcus reached the logarithmic growth phase.

[0054] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Five in that the composition of the artificial seawater in step three (1) is as follows: chloride ions: 18000 mg / L, sodium ions: 10000 mg / L, sulfur ions: 2200 mg / L, magnesium ions: 1000 mg / L, potassium ions: 400 mg / L, calcium ions: 400 mg / L, lead: 0.04 mg / L, cadmium: 0.01 mg / L, mercury: 0.01 mg / L, arsenic: 0.01 mg / L, nitrite: 0.30 mg / L, hexavalent chromium: 0.009 mg / L, reactive phosphate: 0.09 mg / L, with the remainder being water.

[0055] Specific Implementation Method 10: This implementation method differs from Specific Implementation Method 5 in that: the composition of the Thiobacillus culture medium in step 3 (1) is: yeast powder 5g / L, tryptone 10g / L, sodium chloride 10g / L, sodium thiosulfate 10g / L, agar powder 15-20g / L, and deionized water as the solvent; the composition of the Staphylococcus culture medium is: ammonium chloride 0.5g / L, sodium thiosulfate 20g / L, ferrous sulfate 0.01g / L, potassium nitrate 5g / L, magnesium sulfate 0.6g / L, disodium hydrogen phosphate 3.025g / L, calcium chloride 0.05g / L, potassium dihydrogen phosphate 2g / L, manganese sulfate 0.02g / L, sodium bicarbonate 1g / L, agar powder 15-20g / L, and deionized water as the solvent.

[0056] Specific Implementation Method Eleven: This implementation method differs from Specific Implementation Method One in that: the Thiobacillus is Thiobacillus denitrification, Thiobacillus ferrooxidizing acidic acid, Thiobacillus oxidizing sulfuric acid, Thiobacillus thiophanate-depleting, or Thiobacillus acidophilus; the Staphylococcus is Staphylococcus aureus, Vibrio desulfurans, Microbacterium desulfurans, Bacillus desulfurans, Enterobacter desulfurans, or Archaeococcus.

[0057] Example 1:

[0058] This embodiment of the concrete microbial corrosion simulation device in a marine environment consists of a bacterial seawater chamber (1), a corrosion reaction chamber (2), and a waste gas treatment chamber (3). The corrosion reaction chamber (2) is equipped with a mixer (5), an atomizing nozzle (6), a heater (12), and a stainless steel sample holder. The outer side wall of the corrosion reaction chamber (2) is provided with a sampling port (15) and a spray liquid outlet. The atomizing nozzle (6) is connected to the spray liquid outlet through a spray pipe (13), and a pressure pump (14) is provided on the spray pipe (13). The atomizing nozzle (6) is located inside the corrosion reaction chamber (2). At the top, the heater (12) is located at the bottom of the corrosion reaction chamber (2), and the stainless steel sample holder is composed of multiple partitions; the upper part of the corrosion reaction chamber (2) is symmetrically provided with a first gas pipe (25) and a second gas pipe (17); the outlet of the first gas pipe (25) is connected to the inlet of the corrosion reaction chamber (2), and the inlet of the first gas pipe (25) is connected to the atmosphere; the first gas pipe (25) is sequentially provided with a first vacuum pump (24), a first gas solenoid valve (26) and a first gas check valve (27); the first vacuum pump (24 ... second gas pipe (17) is connected to the first gas pipe (27). The inlet end of a gas pipeline (25) is connected to the outlet of a corrosion reaction chamber (2), and the outlet end of the second gas pipeline (17) is connected to the inlet of a waste gas treatment chamber (3); a second vacuum pump (16), a second gas solenoid valve (18), and a second gas check valve (19) are sequentially installed on the second gas pipeline (17); the second vacuum pump (16) is located on the inlet end of the second gas pipeline (17); the upper part of the corrosion reaction chamber (2) is connected to the upper part of the bacteria-containing seawater chamber (1) through a gas connecting pipe (7); The lower part of the corrosion reaction chamber (2) is connected to the lower part of the bacteria-containing seawater chamber (1) through a first liquid pipe (11) and a second liquid pipe (23); a first liquid check valve (8), a first liquid solenoid valve (9) and a first peristaltic pump (10) are sequentially installed on the first liquid pipe (11), and the first peristaltic pump (10) is installed on one side of the corrosion reaction chamber (2); a second peristaltic pump (20), a second liquid solenoid valve (21) and a second liquid check valve (22) are sequentially installed on the second liquid pipe (23), and the second peristaltic pump (20) is installed on one side of the bacteria-containing seawater chamber (1).

[0059] The waste gas treatment chamber (3) is filled with hydrogen sulfide adsorption material; the hydrogen sulfide adsorption material is activated carbon;

[0060] The bacterial seawater tank (1) stores seawater containing acid-producing microorganisms; the acid-producing microorganisms are denitrifying thiobacillus and Staphylococcus aureus;

[0061] The bacterial seawater tank (1) is made of PE; the bacterial seawater tank (1) serves as the storage tank for bacterial seawater in the corrosion reaction tank;

[0062] The method for simulating microbial corrosion of concrete in a marine environment in this embodiment is carried out according to the following steps:

[0063] I. Preparation of concrete specimens

[0064] (1) Weigh the raw materials according to the designed concrete specimen mix proportion. The raw materials are coarse aggregate, fine aggregate, mineral powder, fly ash, ordinary Portland cement, water, water-reducing agent and defoamer. Add the coarse aggregate, fine aggregate, mineral powder, fly ash and ordinary Portland cement to the horizontal twin-shaft mixer in sequence for dry mixing. The time interval between adding each raw material is 60 seconds. Mix the water, water-reducing agent and defoamer and add them evenly to the mixer. Then mix for 5 minutes until the mixture is uniform and has good fluidity.

[0065] The mix proportion of the concrete specimens is as follows: by mass ratio, ordinary Portland cement: fine aggregate: coarse aggregate: mineral powder: fly ash: water: water-reducing agent: defoamer = 270:800:1200:90:90:89.1:1:0.1;

[0066] The ordinary Portland cement is P·O42.5 ordinary Portland cement, produced by Harbin Yatai Company;

[0067] The fine aggregate is river sand with a fineness modulus of 2.6;

[0068] Coarse aggregate is continuously graded crushed stone with a particle size of 5-10 mm;

[0069] The mineral powder is S95 mineral powder, produced by Yantai Anda Environmental Protection Technology Co., Ltd.

[0070] The fly ash is grade II fly ash, produced by Yantai Anda Environmental Protection Technology Co., Ltd.

[0071] The water-reducing agent is a polycarboxylate-based high-efficiency water-reducing agent manufactured by MB Solutions. It is a viscous liquid with a solid content of 50%.

[0072] The defoamer is tributyl phosphate, produced by Xilong Scientific Co., Ltd.

[0073] (2) Pour the concrete mixture obtained from mixing into a mold coated with release agent in one go, place it on a vibrating table and vibrate for 2 minutes. During the vibration process, use a trowel to tamp the mixture along the inner wall of the mold, and make the mixture higher than the upper edge of the mold. Then smooth the surface of the specimen to ensure that the specimen is dense, cover it with plastic wrap and make a mark.

[0074] (3) According to the "Standard for Test Methods of Physical and Mechanical Properties of Concrete" (GB / T 50081-2019) and the "Standard for Quality Control of Concrete" (GB50164-2011), the specimens were cured at room temperature for 24 to 48 hours until they solidified and were demolded. The demolded specimens were immediately placed in a standard curing room for curing until 28 days of age. The temperature of the curing room was 20℃±2℃ and the relative humidity was above 95%, resulting in multiple concrete specimens.

[0075] 2. Weigh the concrete specimens using an electronic precision balance and test the dynamic elastic modulus before corrosion; the dynamic elastic modulus of the concrete specimens before corrosion is 9.67 GPa.

[0076] III. Microbial Corrosion Simulation of Concrete

[0077] (1) In the bacteria-containing seawater tank (1), the atmospheric zone, tidal zone and total immersion zone are divided from top to bottom according to the height;

[0078] The total immersion zone is between 0 and 50 cm in height inside the bacteria-containing seawater tank (1), the tidal zone is between 50 and 100 cm in height inside the bacteria-containing seawater tank (1), and the atmospheric zone is between 100 cm and 150 cm inside the bacteria-containing seawater tank (1). Multiple concrete specimens are placed on stainless steel sample holders at different heights in the bacteria-containing seawater tank (1).

[0079] (2) Store seawater containing acid-producing microorganisms in the bacteria-containing seawater tank (1) and adjust the water level of the corrosion reaction tank (2) to the bottom height of the tidal zone; use heater (12) to control and maintain the temperature inside the corrosion reaction tank (2) at a constant 30°C; use mixer (5) to stir the seawater containing acid-producing microorganisms, start the mixer (5) twice a day for 2 hours each time and stop for 10 hours each time; use atomizing nozzle (6) to spray the seawater containing acid-producing microorganisms in the corrosion reaction tank (2) to the atmospheric zone and the tidal zone, and maintain the humidity of the atmospheric zone and the tidal zone at 100%RH;

[0080] The method for preparing the seawater containing acid-producing microorganisms is as follows: First, prepare 160L of artificial seawater. Then, mix 1600g of Thiobacillus denitrification culture medium and 1600g of Staphylococcus aureus culture medium evenly and add them to the artificially prepared seawater. Irradiate with ultraviolet light for 12 hours, and then add 400mL of a solution with a concentration of 2.98×10⁻⁶. 8 CFU / mL of Thiobacillus denitrification bacterial solution and 400 mL of solution with a concentration of 3.06×10 8 The Staphylococcus aureus bacterial suspension at CFU / mL showed that both Thiobacillus denitrificationis and Staphylococcus aureus in the suspension had reached the logarithmic growth phase.

[0081] The artificial seawater contains the following components: chloride ions: 18000 mg / L, sodium ions: 10000 mg / L, sulfur ions: 2200 mg / L, magnesium ions: 1000 mg / L, potassium ions: 400 mg / L, calcium ions: 400 mg / L, lead: 0.04 mg / L, cadmium: 0.01 mg / L, mercury: 0.01 mg / L, arsenic: 0.01 mg / L, nitrite: 0.30 mg / L, hexavalent chromium: 0.009 mg / L, reactive phosphate: 0.09 mg / L, with the remainder being water.

[0082] The composition of the *Thiobacillus denitrification* culture medium is: 5 g / L yeast extract, 10 g / L tryptone, 10 g / L sodium chloride, 10 g / L sodium thiosulfate, and 15-20 g / L agar powder, with deionized water as the solvent; the composition of the *Staphylococcus aureus* culture medium is: 0.5 g / L ammonium chloride, 20 g / L sodium thiosulfate, 0.01 g / L ferrous sulfate, 5 g / L potassium nitrate, 0.6 g / L magnesium sulfate, 3.025 g / L disodium hydrogen phosphate, 0.05 g / L calcium chloride, 2 g / L potassium dihydrogen phosphate, 0.02 g / L manganese sulfate, 1 g / L sodium bicarbonate, and 15-20 g / L agar powder, with deionized water as the solvent;

[0083] Staphylococci reduce sulfate, sulfite, thiosulfate, and elemental sulfur to hydrogen sulfide; Thiobacillus oxidizes various reduced sulfides, such as hydrogen sulfide or elemental sulfur, to bio-sulfuric acid under low pH conditions. This embodiment uses *Staphylococcus aureus* and *Thiobacillus denitrificans* as synergistic corrosion bacteria to simulate the microbial corrosion environment in a real marine setting. *Staphylococcus aureus* was obtained from the Marine Corrosion and Protection Open Laboratory of the Institute of Oceanology, Chinese Academy of Sciences. This bacterium uses thiosulfate as a sulfur source to produce cysteine, which is then further decomposed to produce hydrogen sulfide. *Thiobacillus denitrificans* was purchased from Ningbo Taisto Biotechnology Co., Ltd. This bacterium uses oxygen as an electron acceptor to hydrogenate the sulfide produced by *Staphylococcus aureus* to elemental sulfur, and then further oxidizes the sulfur to the final product, sulfuric acid.

[0084] (3) The tidal process is simulated by draining water through the first peristaltic pump (10) and supplying water through the second peristaltic pump (20). The tidal process includes the following cycle: the seawater level drops from the top of the tidal zone to the bottom of the tidal zone (11h55min), the seawater level is at the bottom of the tidal zone (5min), the seawater level rises from the bottom of the tidal zone to the top of the tidal zone (11h55min), and the seawater level is at the top of the tidal zone (5min). During this period, 50% of the seawater containing acid-producing microorganisms is replaced every 15 days. At the same time, air is drawn from the atmosphere and sent into the corrosion reaction chamber (2) through the first vacuum pump (24), and hydrogen sulfide gas is extracted through the second vacuum pump (16) to ensure that the oxygen concentration in the chamber is maintained at 18-20.5% of the O2 volume concentration. The hydrogen sulfide gas is adsorbed and removed in the waste gas treatment chamber (3).

[0085] 4. After 150 days, the concrete specimens simulated in step 3 (atmospheric zone, tidal zone, and full immersion zone) were removed, and the biofilm on the surface of the concrete specimens was separated. Biofilm thickness test and staining test of live and dead bacteria on the biofilm surface were performed. The thickness of the biofilm on the specimen surface in the tidal zone and full immersion zone is shown in Table 5. As can be seen from Table 5, microorganisms grow and attach to the surface of the specimens and form a biofilm. Figure 5 This is a diagram showing the distribution of live and dead bacteria staining in the biofilm of the specimen in the tidal zone after 150 days of corrosion. Figure 6 The image shows the distribution of live and dead bacteria in the biofilm of the specimen after 150 days of corrosion in the fully immersed zone. The staining test of live and dead bacteria on the biofilm surface shows that a large number of live microorganisms are attached to the surface of the specimen, which is consistent with the actual marine environment, indicating that the equipment simulation effect is good.

[0086] 5. After cleaning the biofilm off the surface of the concrete specimens, place them indoors to dry, then weigh them and perform tests on the dynamic elastic modulus, flexural strength, compressive strength, XRD, and porosity after corrosion.

[0087] In Example 1, concrete specimens were placed in the atmospheric zone, tidal zone, and fully immersed zone of a corrosion chamber for 150 days for corrosion, and then their flexural strength, compressive strength, dynamic elastic modulus, porosity, and XRD were tested. A control group was also set up. The control group was different from Example 1 in that it contained seawater without acid-producing microorganisms in the bacterial seawater chamber (3). The results are shown in Tables 1-3. The porosity parameters of the specimens in the fully immersed zone before and after 150 days of microbial corrosion are shown in Table 4. The corrosion effects in the fully immersed zone and the tidal zone were the most obvious. The maximum loss rate of flexural strength of the concrete in the fully immersed zone after 150 days of corrosion reached 20.8%, because the microbial activity and concentration were higher in the fully immersed zone, resulting in stronger corrosion. The maximum loss rate of dynamic elastic modulus of the concrete in the tidal zone after 150 days of corrosion reached 61.4%, because the physical-chemical multi-scale damage caused by alternating wet and dry conditions caused the greatest damage to the internal structure of the concrete matrix. The total pore volume, porosity, most probable pore diameter, and volumes of harmful and frequently harmful pores in the concrete specimens generally showed a gradual increasing trend over time. This is related to the decomposition of internal hydration products caused by biological sulfuric acid corrosion, and the internal stress induced by the expansion of excessive gypsum and ettringite. The above data are largely close to the actual marine environment, further demonstrating that this invention has a good simulation effect on the atmospheric zone, tidal zone, and fully submerged zone of the marine environment in situ.

[0088] Figure 3 The XRD pattern of the fully immersed specimen before microbial corrosion is shown. Figure 4 The XRD pattern of the fully immersed specimen after 150 days of microbial corrosion is shown. Figure 3 and Figure 4 It can be seen that the main components of microbially corroded concrete include dicalcium silicate (C2S), ettringite, Ca(OH)2, and CaCO3. As corrosion progresses, the acid produced by microorganisms erodes the concrete, causing instability of internal hydration products. The content of C2S gradually decreases, while the content of ettringite and CaCO3 gradually increases to 13.5% and 11%, respectively. This, in turn, leads to specimen expansion, induces internal stress, and causes microcrack propagation, providing a channel for microbial invasion. As the acid-producing corrosion by microorganisms continues to penetrate deeper, the strength of the specimen gradually decreases. This phenomenon is consistent with the actual marine environment.

[0089] Table 1

[0090]

[0091] Table 2

[0092]

[0093] Table 3

[0094]

[0095] Table 4

[0096]

[0097] Table 5

[0098]

Claims

1. A device for simulating microbial corrosion of concrete in a marine environment, characterized in that: The marine environment concrete microbial corrosion simulation device consists of a bacterial seawater chamber (1), a corrosion reaction chamber (2), and a waste gas treatment chamber (3). The corrosion reaction chamber (2) is equipped with a mixer (5), an atomizing nozzle (6), a heater (12), and a stainless steel sample holder. The outer side wall of the corrosion reaction chamber (2) is equipped with a sampling port (15) and a spray liquid outlet. The atomizing nozzle (6) is connected to the spray liquid outlet through a spray pipe (13), and a pressure pump (14) is installed on the spray pipe (13). The atomizing nozzle (6) is located at the top inside the corrosion reaction chamber (2), and the heater (12) is located at the top inside the corrosion reaction chamber (2). The bottom of the corrosion reaction chamber (2) is supported by a stainless steel sample holder made of multiple partitions; the upper part of the corrosion reaction chamber (2) is symmetrically equipped with a first gas pipe (25) and a second gas pipe (17); the outlet of the first gas pipe (25) is connected to the inlet of the corrosion reaction chamber (2), and the inlet of the first gas pipe (25) is connected to the atmosphere; a first vacuum pump (24), a first gas solenoid valve (26) and a first gas check valve (27) are sequentially installed on the first gas pipe (25); the first vacuum pump (24) is located on one side of the inlet of the first gas pipe (25); the second gas pipe The inlet of (17) is connected to the outlet of the corrosion reaction chamber (2), and the outlet of the second gas pipe (17) is connected to the inlet of the waste gas treatment chamber (3); a second vacuum pump (16), a second gas solenoid valve (18), and a second gas check valve (19) are sequentially installed on the second gas pipe (17); the second vacuum pump (16) is located on one side of the inlet of the second gas pipe (17); the upper part of the corrosion reaction chamber (2) is connected to the upper part of the bacteria-containing seawater chamber (1) through a gas connecting pipe (7); the lower part of the corrosion reaction chamber (2) is connected to the lower part of the bacteria-containing seawater chamber (1) through a first liquid pipe (11). The first liquid pipeline (11) is connected to the second liquid pipeline (23); the first liquid pipeline (11) is sequentially equipped with a first liquid check valve (8), a first liquid solenoid valve (9) and a first peristaltic pump (10), and the first peristaltic pump (10) is located on one side of the corrosion reaction chamber (2); the second liquid pipeline (23) is sequentially equipped with a second peristaltic pump (20), a second liquid solenoid valve (21) and a second liquid check valve (22), and the second peristaltic pump (20) is located on one side of the bacteria-containing seawater chamber (1), which stores seawater containing acid-producing microorganisms; the acid-producing microorganisms are Staphylococcus aureus and Thiobacillus thiobacillus; The waste gas treatment chamber (3) is filled with hydrogen sulfide adsorption material.

2. The marine environment concrete microbial corrosion simulation device according to claim 1, characterized in that: The thiobacilli are denitrifying thiobacilli, ferrous acid thiobacilli, sulfuric acid thiobacilli, sulfur-excreting thiobacilli, and acidophilic thiobacilli; the staphylococci are Staphylococcus aureus, desulfurized Vibrio, desulfurized Microbes, desulfurized Bacillus, desulfurized Enterobacteriaceae, and Archaeococcus.

3. The marine environment concrete microbial corrosion simulation device according to claim 1, characterized in that: The hydrogen sulfide adsorbent material is activated carbon, zinc oxide, or iron oxide.

4. A method for simulating microbial corrosion of concrete in a marine environment using the microbial corrosion simulation device described in claim 1, characterized in that: This method is performed according to the following steps: I. Preparation of concrete specimens (1) Weigh the raw materials according to the designed concrete specimen mix proportion. The raw materials are coarse aggregate, fine aggregate, mineral powder, fly ash, ordinary Portland cement, water, water-reducing agent and defoamer. Add the coarse aggregate, fine aggregate, mineral powder, fly ash and ordinary Portland cement to the horizontal twin-shaft mixer in sequence for dry mixing. The time interval between adding each raw material is 60 seconds. Mix the water, water-reducing agent and defoamer and add them evenly to the mixer. Then mix for 5 minutes until the mixture is uniform and has good fluidity. (2) Pour the mixed concrete into a mold coated with release agent in one go, and place it on a vibrating table to vibrate for 2 minutes; (3) Curing was carried out to obtain multiple concrete specimens; 2. Weigh the concrete specimens using an electronic precision balance and perform a dynamic elastic modulus test before corrosion. III. Microbial Corrosion Simulation of Concrete (1) The seawater tank (1) containing bacteria is divided into atmospheric zone, tidal zone and full immersion zone according to the height from top to bottom; multiple concrete specimens are placed on stainless steel sample holders at different heights in the atmospheric zone, tidal zone and full immersion zone of the seawater tank (1) containing bacteria. (2) Store seawater containing acid-producing microorganisms in the bacteria-containing seawater tank (1) and adjust the water level of the corrosion reaction tank (2) to the bottom height of the tidal zone; use heater (12) to control and maintain the temperature inside the corrosion reaction tank (2) at the set temperature; use mixer (5) to stir the seawater containing acid-producing microorganisms, start the mixer (5) twice a day for 2 hours each time and stop for 10 hours each time; use atomizing nozzle (6) to spray the seawater containing acid-producing microorganisms in the corrosion reaction tank (2) to the atmospheric zone and the tidal zone, and maintain the humidity of the atmospheric zone and the tidal zone at 100%RH; (3) The tidal process is simulated by draining water through the first peristaltic pump (10) and supplying water through the second peristaltic pump (20). The tidal process includes the following cycle: the seawater level drops from the top of the tidal zone to the bottom of the tidal zone, the seawater level remains at the bottom of the tidal zone for a period of time, the seawater level rises from the bottom of the tidal zone to the top of the tidal zone, and the seawater level remains at the top of the tidal zone for a period of time. During this period, the seawater containing acid-producing microorganisms is renewed every 15 days. At the same time, air is drawn from the atmosphere and sent into the corrosion reaction chamber (2) through the first vacuum pump (24), and hydrogen sulfide gas is extracted through the second vacuum pump (16) to ensure that the oxygen concentration in the chamber is maintained at 18-20.5% and the O2 volume concentration is controlled at 18-20.5%. The hydrogen sulfide gas is adsorbed and removed in the waste gas treatment chamber (3).

4. Take out the concrete specimens that have been simulated in step 3 (atmospheric zone, tidal zone, and total immersion zone), separate the biofilm on the surface of the concrete specimens, and conduct biofilm thickness test and biofilm surface staining test for live and dead bacteria.

5. After cleaning the biofilm off the surface of the concrete specimens, place them indoors to dry, then weigh them and perform tests on the dynamic elastic modulus, flexural strength, compressive strength, XRD, and porosity after corrosion.

5. The method for simulating microbial corrosion using a concrete microbial corrosion simulation device in a marine environment, as described in claim 4, is characterized in that: The mix proportion of the concrete specimen in step one (1) is as follows: by mass ratio, ordinary Portland cement: fine aggregate: coarse aggregate: mineral powder: fly ash: water: water-reducing agent: defoamer = 170-370: 750-900: 1100-1300: 50-150: 50-150: 80-90: 0.6-1.2: 0.01-0.

2.

6. The method for simulating microbial corrosion using a concrete microbial corrosion simulation device in a marine environment, as described in claim 4, is characterized in that: Step 3 (1) The full immersion zone is between 0 and 50 cm in height inside the bacteria-containing seawater tank (1), the tidal zone is between 50 and 100 cm in height inside the bacteria-containing seawater tank (1), and the atmospheric zone is between 100 cm and 150 cm inside the bacteria-containing seawater tank (1).

7. The method for simulating microbial corrosion using a concrete microbial corrosion simulation device in a marine environment, as described in claim 4, is characterized in that: Step 3 (1) The method for preparing seawater containing acid-producing microorganisms is as follows: First, prepare 160L of artificial seawater. Then, mix 1600g of Thiobacillus culture medium and 1600g of Staphylococcus culture medium evenly and add them to the artificially prepared seawater. Irradiate with ultraviolet light for 12 hours. Then, add 400mL of a solution with a concentration of 2.98×10⁻⁶. 8 CFU / mL Thiobacillus bacterial suspension and 400 mL of 3.06×10⁻⁶ CFU / mL Thiobacillus bacterial suspension 8 The staphylococcal culture solution at CFU / mL showed that both Thiobacillus and Staphylococcus reached the logarithmic growth phase.

8. The method for simulating microbial corrosion using a concrete microbial corrosion simulation device in a marine environment, as described in claim 7, is characterized in that: The artificial seawater in step three (1) consists of the following components: chloride ions: 18000 mg / L, sodium ions: 10000 mg / L, sulfur ions: 2200 mg / L, magnesium ions: 1000 mg / L, potassium ions: 400 mg / L, calcium ions: 400 mg / L, lead: 0.04 mg / L, cadmium: 0.01 mg / L, mercury: 0.01 mg / L, arsenic: 0.01 mg / L, nitrite: 0.30 mg / L, hexavalent chromium: 0.009 mg / L, reactive phosphate: 0.09 mg / L, with the remainder being water.

9. The method for simulating microbial corrosion using a concrete microbial corrosion simulation device in a marine environment, as described in claim 7, is characterized in that: Step 3 (1) The composition of the Thiobacillus culture medium is: yeast powder 5g / L, tryptone 10g / L, sodium chloride 10g / L, sodium thiosulfate 10g / L, agar powder 15-20g / L, and deionized water as the solvent; the composition of the Staphylococcus culture medium is: ammonium chloride 0.5g / L, sodium thiosulfate 20g / L, ferrous sulfate 0.01g / L, potassium nitrate 5g / L, magnesium sulfate 0.6g / L, disodium hydrogen phosphate 3.025g / L, calcium chloride 0.05g / L, potassium dihydrogen phosphate 2g / L, manganese sulfate 0.02g / L, sodium bicarbonate 1g / L, agar powder 15-20g / L, and deionized water as the solvent.

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