Identifying Alkali-Silica Reaction in Cementitious Materials Using Volatilomics

For millennia, the medical field has utilized the sense of smell for qualitative assessment of health, but recent research shows we can tap into volatile organic compounds (VOCs), which create the odors that we perceive, for quantitative detection and analysis. In this paper, volatile organic compounds produced by the microbes in aged concrete, actively undergoing deterioration due to alkali-silica reaction were analyzed. Volatile organic compounds metabolites, an oft unused resource of chemical information that are produced by concrete-associated microbial communities, were used to detect, and characterize concrete deterioration. In this talk, preliminary results of volatile detection on long-term samples (e.g., ~ 7 years) will be provided. Scanning electron microscopy with energy disperse x-ray analysis was used to confirm deterioration mechanisms identified using volatilomics. Volatiles were analyzed using direct thermal extraction (DTE) and comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry (GC × GC–TOFMS).

Identifying VOC biomarkers of concrete health will lay the groundwork for the development of sensors that can provide early deterioration warning, enabling more effective remediation/repair strategies. Microbes may also be sensitive to environmental stress (e.g., climate change), and a sensor based on microbial volatile organic compounds could be used to monitor infrastructure health and provide data to detect environmental stressors relevant to other fields.