Durability of cement-based materials in drinking water storage

In order to provide a hygienic storage drinking water reservoirs have been coated with mineral mortar linings in all epochs of European history. However, modern cement-based materials often show in this special operational environment an inadequate durability. Even though drinking water is commonly not considered particularly harmful to cementitious systems, the chemical degradation of mortar linings in drinking water storage systems can occur very fast compared to other common deterioration reactions. This results in cost intensive repair measures and thus high life-cycle costs as well associated with an ecological burden. Furthermore, an insufficient understanding of degradation mechanisms and their underlying physical, chemical as well as biological processes currently impedes performance-oriented approaches to improve durability. In this regard a research project aims to unravel the potentially combined multiple deterioration mechanisms, integrating results of case studies and laboratory experiments. In this context a specific issue of this research activity is to evaluate the applicability of an accelerated degradation test that takes advantage of the impact of electrical fields on the stability of cement-based materials in permanent contact to aqueous environments. ... mehrLaboratory experiments show, that such tests are suitable to compare the resilience against reactive transport processes of materials and to draw conclusions regarding their performance, illustrating material changes in terms of depth and time. Furthermore, the results indicate, that the transport properties of the rim zone of cement-based materials are regulating its sturdiness in aggressive aqueous environments. This approach appears therefore suitable for a performance assessment in material development and provides as well new impulses for quality control in practice paving the path for increased durability of materials applied in drinking water supply infrastructure.