In vitro deterioration study of concrete and marble by Aspergillus tamarii

Abstract Fungal deterioration is a major concern of conserving building materials. The objective of this paper was to investigate the effect of fungal deterioration of concrete and marble under conditions favourable for the development of microorganisms. Towards this aim, concrete (10 cm x 10 cm x 10 cm) and marble cubes (5 cm x 5 cm x 5 cm) were inoculated with pure cultures of Aspergillus tamarii isolated from Tagore house. Physical, chemical and aesthetic qualities were measured over 180 days. The results showed that reductions of weight for concrete and marble cubes were 1.20% and 1.90% respectively whereas compressive strength loss for both cubes were 24.32% and 19.15% respectively. The Scanning Electron Microscope (SEM) images distinctly exhibit the fungal growth in form of calcium oxalate crystal, increase in porosity and extension of fungal hyphae into interior of both cubes responsible in crack formation. The elemental composition analysis as conducted by micro Energy Dispersive X-ray Fluorescence (EDXRF) exhibited reduction of mass fraction of calcium for concrete (25.93%) and marble (10.19%) as compared to the control powder samples. The infrared (IR) spectral analysis of both samples showed absence of several spectral bands after 180 days which confirmed the fungal invasion for elimination of functional groups and also confirmed deterioration potentiality of the selected fungal species.