Study of reinforcement corrosion in expanded clay concrete

Abstract

Expanded clay concrete differs from heavy-weight concrete not only by the composition and performance properties, but also by modes of chemical interactions between the components. So, not the primary problem of reinforcement corrosion in heavy-weight concrete under the normal conditions and the correct protective layer, becomes in the major problem in expanded clay concrete. The issue of reinforcement corrosion in expanded clay concrete is considered in this article. The studies on the effect of different compositions on the corrosiveness were conducted. Researchers have proposed various options for expanded clay concrete reinforcement protection from the environmental impact, including those through a variety of chemically active additives. According to the data obtained by experimenting, the diagrams of corroded area size dependence on various factors were presented.The results of the studies conducted are the recommended design and technological measures for the reinforcement protection against corrosion in various fine aggregate-based (natural sand, ash and dry hydroremoval) light-weight expanded clay concrete. Thus, the minimum concrete protective cover for main and distribution reinforcement of external walls must be at least 25mm. It is necessary to inject additives – reinforcement corrosion inhibitors (sodium nitrite, sodium tetraborate) to the concrete composition. The consumption of cement, and hence, the cement paste content of concrete mixture must be not lower than 220kg/m3, and under the application of the active dry fly ash removal −200kg/m3.