Open AccessSimulation of accelerated concrete destruction by inoculation of an association of bacteria of the genus Thiobacillus
Author(s) -
Е. В. Фомина,
С. В. Свергузова,
Е. Н. Гончарова,
I. Flores-Vivián
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/945/1/012008
Subject(s) - leaching (pedology) , thiobacillus , sulfuric acid , sulfur , aqueous solution , corrosion , nuclear chemistry , chemistry , materials science , metallurgy , biology , ecology , organic chemistry , soil water
The mechanisms of biogenic destruction of concrete under the influence of microbiological corrosion are described. An accelerated method of inoculation of the association of sulfur-oxidizing thionic bacteria Thiobacillus thioparus and Thiobacillus thiooxidans was used. Beyerink solution was used as a nutrient medium. The impact of two types of microorganisms in model systems imitates microbiocorrosion conditions; this allows reducing the test time and predicting the mechanisms of concrete destruction during operation. The active development of Thiobacilus thioparus promotes the leaching of concrete, further bacteria of the genus Thiobacilus thiooxidans appear with a decrease in pH, and both species actively synthesize sulfuric acid. The kinetics of the bio corrosion process was monitored for 60 days. The bacterial adaptation period is 16–18 days, after which the pH of the aqueous medium decreases. The rate of formation of a biological acid in an aqueous medium determines the leaching of Mg 2+ , Ca 2+ , and SO 4 2 − ions from concrete. Concrete when exposed to bio acids for two months loses 30% of its strength. The microstructure analysis of bio corrosion products on the concrete surface was carried out with the help of a scanning electron microscope.