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Blast furnace slag (BFS) is used for preparation of common cements, sulfate-resisting and chemical-resisting cements and cement mortars. Using BFS as a concrete or mortar addition results in several advantageous properties such as high resistance to acid attack (sulphuric, nitric acids), low chloride permeability, high durability and low capillary porosity. Because of these properties using BFS in cement composites can decrease the effect of biodegradation induced by various microorganisms. Bio-corrosion is caused by biogenic organic and mineral acids, which result from metabolic activity of microorganisms like fungi, bacteria or yeasts. In this article, the potential antifungal properties of BFS were analysed regarding the selected species of fungi (Cladosporium spp., Aspergillus niger and Penicillium glabrum). Antifungal efficiency was studied on cement composites with different share (65%, 75%, 85% and 95%) of BFS. Moderate antifungal effectivity of composites with slag was confirmed for two from three strains of studied fungi Cladosporium spp. and Aspergillus niger. [ABSTRACT FROM AUTHOR]

The corrosion processes of mineral, metal and polymeric building materials can be influenced by biological factors. The effect of bio-agents on the construction materials in recent years is the subject of scientific interest. Scientific approach particularly relating to the surface changes of corroded materials requires the development of diagnostic methods of interdisciplinary character. Current research in the field is aimed with respect to the potential of innovative diagnostic techniques in microscopy, new spectroscopic and other techniques for the study of corrosion products and biofilms. This paper aims to present the results of the evaluation of concrete durability affected by bacterial corrosion. The X-ray fluorescence analysis (XRF), infrared analysis (FTIR), thermal analysis (TG/DSC) and atomic force microscopy (AFM) were used for the investigation of the concrete samples before and after the experiments. The experiments proceeded in real sewage system during 6 months. The sulphur-oxidising and sulphate reducing bacteria present in waste water was considered to be the main corrosion factor. The corrosion process has been demonstrated by the tensile strength changes of concrete samples as well as by the chemical composition changes. [ABSTRACT FROM AUTHOR]