Affirmative nanosilica mediated approach against fungal biodeterioration of concrete materials

Abstract

Microbial biodeterioration has been an important concern for concrete buildings’ durability over time. This study primarily emphasizes on the fungal biodeterioration of concrete and the effectiveness of silicon dioxide nanocoating on concrete in inhibiting fungal growth. A nanosilica coating was optimised and applied on concrete cube surface that was in turn infected with Aspergillus tamarii and monitored physical, mechanical, chemical as well as visual changes for a period of six months. The visual analysis included colour changes, Stereo Microscopy and Scanning Electron Microscopy (SEM) which showed a considerable change on the surface deterioration. Weight loss showed positive in all the concrete specimens (2.08% for biodeteriorated cubes and 2.13% for nanocoated cubes) whereas compressive strength that increased, 35.01% in nanocoated concrete cubes and 24.72% in biodeteriorated cubes. The chemical analysis included pH change in media, Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-Ray Fluorescence Spectroscopy (EDXRF) which showed that leaching of calcium ions from the concrete in biodeteriorated cubes was higher than that of nanocoated cubes. Altogether the efficacy of silicon oxide nanocoating against biodeterioration of concrete by Aspergillus tamarii was concluded to be positive.

Keywords

• Biodeterioration
• Nanosilica
• Concrete
• SEM
• EDXRF
• Aspergillus tamarii