Method for improving microbial corrosion resistance of concrete

Abstract

The invention discloses a method for improving microbial corrosion resistance of concrete. The method comprises the following steps: immersing concrete with built-in steel bars in a copper lactate electrolyte of a direct-current electrolysis device, and performing direct-current electrolysis by taking the steel bars in the concrete as a cathode; and cleaning and blow-drying the electrolyzed concrete, soaking the concrete in a dopamine solution and a 1-dodecanethiol solution for coating sequentially, and taking the concrete out for cleaning and blow drying. The microbial corrosion resistance ofthe concrete is improved by depositing copper and copper oxide on the surface of concrete; by addition of a composite coating to the surface of deposit, hydrophobicity of the test piece surface is improved, leaching of copper ions is reduced, and the service life of the deposit is prolonged. The electrolyte prepared from copper nitrate instead of copper sulfate prevents the influence of sulfate ions on performance of the concrete during electrodeposition. The concrete electrodeposition method and device have the advantages of simple structure, simple and convenient operation, good anticorrosion effect, high practicability and wide applicability.

Description

technical field [0001] The invention belongs to the field of durability of concrete structures, and in particular relates to a method for improving the anti-microbial corrosion performance of concrete. Background technique [0002] Microbial corrosion is one of the main causes of damage to concrete sewage pipelines. Sewage and the sludge layer accumulated at the bottom of the pipeline contain a large number of bacteria, among which sulfate-reducing bacteria and sulfate-oxidizing bacteria are extremely harmful to concrete. The sulfuric acid produced by their metabolism reacts chemically with cement hydration. On the one hand, it generates expansive ettringite and gypsum, causing micro-cracks inside the concrete; on the other hand, the reaction consumes a large amount of Ca(OH) 2 , reduces the pH value of concrete and destroys the passivation film of steel bars. Concrete erosion caused by microorganisms not only causes huge economic losses, but also seriously damages the str...

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Problems solved by technology

[0006] 2. Previous studies mainly focused on improving the purity of cuprous oxide, resulting in very low copper content deposited on the concrete surface, but cuprous oxide is easily oxidized to CuO in actual sewage pipes, and Cu and CuO also have good bactericidal properties. Therefore, increasing the content of copper on the surface of concrete is the key to antimicrobial performance;

[0008] 4. Under the scouring of sewage, the cuprous oxide and copper oxide deposited on the concrete surface are easy to leach, resulting in a low service life of the coating, so it needs to be re-deposited for follow-up treatment to improve its durability

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