Microscopic study into biodeterioration of marine concrete

This research presents an exploratory study into the biodeterioration of marine concrete. Monocular and inverted light microscopy, scanning electron microscopy (SEM) with energy dispersive X-ray analyser (EDX) were used to observe colonisation of site specimens at the fine aggregate cement interface, enabling the further understanding of this interaction. Algal filaments have been observed growing between fine aggregate and cement. Colonisation has been observed, entangled around, and adhered to fine aggregate. This degradation mechanism occurs when the material bond is weakened as a direct result of the physical activity of an organism, such as its growth. Loss of surface material, either through biodeterioration or through other mechanical means, such as power washing, is not the primary cause of degradation, but may exacerbate the condition.

► Algal filaments can grow freely between fine aggregate and the cement matrix.
► Microbial populations around the surface of the fine aggregate.
► Washing partly removes the biomass present on the surface of the aggregate.