摘要：Vegetation and microorganisms present the biological factors
that deteriorate concrete. These problems are very visible in places like
sewage, underground and hydraulic structures, chemical plants, industrial
structures, liquid-containing structures, agricultural structures or marine
environments. The most significant biodeteriogens are the sulphur-oxidising
bacteria Acidithiobacillus thiooxidans (A. thiooxidans) and the sulphatereducing
bacteria (Desulfovibrio spp.) that are responsible for the so-called
sulphuretum consortium. Microorganisms that produce sulphuric acid
accelerate the deterioration of concrete sewer pipes in a process termed
Microbially Induced Concrete Corrosion (MIC). The paper considers the
assessment of the release of calcium and silicon from concrete composites
with and without coal fly ash by sulphur-oxidizing bacteria. The concrete
mixture contained coal fly ash as 5 wt. % and wt. 10 % cement replacement.
Prepared composites were exposed to an aggressive microbial environment
under laboratory conditions for 3 months. The pH values were measured and
studied during this time period. A different resistance against MIC was
observed for the concrete composites of different compositions. The highest
amount of calcium leached-out from the concrete was in the case of the
composites where 10 % cement was replaced by fly ash.
其他摘要：Vegetation and microorganisms present the biological factors that deteriorate concrete. These problems are very visible in places like sewage, underground and hydraulic structures, chemical plants, industrial structures, liquid-containing structures, agricultural structures or marine environments. The most significant biodeteriogens are the sulphur-oxidising bacteria Acidithiobacillus thiooxidans (A. thiooxidans) and the sulphatereducing bacteria (Desulfovibrio spp.) that are responsible for the so-called sulphuretum consortium. Microorganisms that produce sulphuric acid accelerate the deterioration of concrete sewer pipes in a process termed Microbially Induced Concrete Corrosion (MIC). The paper considers the assessment of the release of calcium and silicon from concrete composites with and without coal fly ash by sulphur-oxidizing bacteria. The concrete mixture contained coal fly ash as 5 wt. % and wt. 10 % cement replacement. Prepared composites were exposed to an aggressive microbial environment under laboratory conditions for 3 months. The pH values were measured and studied during this time period. A different resistance against MIC was observed for the concrete composites of different compositions. The highest amount of calcium leached-out from the concrete was in the case of the composites where 10 % cement was replaced by fly ash.
