Evaluation of the antimicrobial efficiency of slag based composites

Abstract

Abstract Degradation of cement mortar composites occurs due to a variety of causes such as corrosion (sulphate or chloride attack) cracking or shrinkage. Chemical agents often play a major role in corrosion processes, however recent research has revealed the importance of biological agents. Microbiological corrosion is caused by the presence and activities of microorganisms, including algae, bacteria, yeasts and fungi. These microorganisms produce substances like biogenic organic and mineral acids that can disrupt the matrix of mortar composites. The most effective method for improving the resistance of cement based composites is the addition of pozzolans like blast furnace slag. Slag is often used in preparation of cement composites to improve the acid resistance, impermeability and crack resistance of mortars. This article presents the investigation of antimicrobial efficiency of blast furnace slag regarding the selected species of bacteria (Pseudomonas aeruginosa, Micrococcus luteus), yeasts (Candida albicans, Saccharomyces cerevisiae) and algae (Chlorella vulgaris). Antimicrobial properties were studied on mortars with different share of slag (65% - 95%). Antimicrobial efficiency for the tested species of microorganisms was found moderate to low.