Biological Corrosion of Concrete

Abstract

The article considers the results of studies to determine the causes, mechanisms and features of biological corrosion of cement concrete. It has been found that the intensive growth of microorganisms on the surface and in the pores of concrete leads to the formation of corrosive biogenic substances and, as a result, the reduction of alkalinity of cement stone with its subsequent decomposition. The influence of certain types of biogenic substances on the components of cement concrete (biogenic organic acids, biogenic carbon dioxide, biogenic nitric acid, biogenic hydrogen sulphide and sulfuric acid) is considered. Methods for increasing the biological resistance of concrete are described, such as: adding additives that can form buffer systems capable of reducing the impact on cement concretes of acids produced by microorganisms; treating the surface of composites with substances capable of repelling microorganisms and environments necessary for their vital activity; use of active media capable of forming dense and inert layers on the surface of the material. Despite the available methods of increasing the biological resistance of cement concrete, it is not possible to fully guarantee their safety from biocorrosion, at least because microorganisms can adapt to the environment and suspend the effect of protection. In this regard, the work attempts to assess and predict the biological resistance of the material.

Сравнительные Динамические Характеристики Конструкционных Материалов

“…Теоретическим вопросам биокоррозии различных строительных материалов посвящены многочисленные работы. Среди них в первую очередь можно назвать [11][12][13][14][15] При наружном осмотре храма прпп Зосимы и Савватия легко выявляются такие признаки регулярного и длительного увлажнения стен, как развитие водорослей. Наряду с указанными выше еще одной причиной этого может быть неправильное устройство ливневого водостока.…”

Development of technology for obtaining asphalt concrete mixture using oil sludge as an additive

“…Oil sludge, like bitumen, contains 40-60% oils, 20-40% resins, 10-25% asphaltenes, 1-3% carbenes and carboids, as well as a small amount of phenols and paraffin (up to 1%). According to their structure, bitumen belongs to complex colloidal solutions of asphaltenes and part of resins (dispersed phase) in a medium of petroleum oils (dispersion medium) [9].…”

Determination of the degree of microbiological damage to the «Cement Concrete - Steel Reinforcement» system

“…In all biocorrosion processes, the metabolic activity of microorganisms can cause the initiation of chemical and electrochemical reactions and increase the speed of these processes, leading to the corrosive destruction of materials. These mechanisms include acidolysis, which leads to the release of biogenic acids (sulfuric and nitric) into the environment; complexation by biogenic organic acids; redox reactions (including oxidation of iron and manganese ions) and processes of organic matter accumulation and oxygen production [11][12][13][14].…”