Application of Fourier transform infrared spectroscopy to study concrete degradation induced by biogenic sulfuric acid

Fourier transform infrared spectrophotometry (FTIR) was utilized, in order to identify concrete degradation due to biogenic sulfuric acid attack. Concrete samples were exposed to electrolytes containing bio-species in laboratory simulating field conditions and FTIR spectra of the reacted concrete were analyzed for concrete phase formation. The major and minor FTIR absorption bands due to the presence of sulfate were detected in the range of 1200-1100 cm(-1) and 650-600 cm(-1), respectively. In addition FTIR spectra of the concrete samples exposed to acid-producing microorganisms show an overtone band at around 2350 cm(-1) owing to presence of sulfur containing compound in concrete. Results of scanning electron microscopy with energy-dispersive spectrometry complemented and confirmed FTIR analysis.