Non-Ureolytic Bacterial Carbonate Precipitation as a Surface Treatment Strategy on Cementitious Materials

Bacterially induced CaCOз precipitation is a general phenomenon in nature. It has been proposed as an environmentally friendly strategy for the protection of cementitious materials. This paper investigates the biochemistry of CaCOз precipitation induced by non-ureolytic bacteria of the genus Bacillus. Different calcium sources are compared for their effectiveness in bacterial mediation of precipitation. Surface treatment using this biodeposition technique is evaluated by parameters affecting the durability of cementitious materials. Outcomes from this study reveal that the type of calcium source has a profound impact on the biochemical process and the crystal form, size, and morphology of bacterially mediated mineralization of CaCOз. An organic calcium source, particularly calcium glutamate, is beneficial for efficient CaCOз precipitation. Bacterial surface treatment on specimens results in a decrease of more than 50% in capillary water absorption and an increase of nearly 50% in resistance to carbonation; this is mainly attributed to pore blocking effects. This novel biological surface treatment shows particularly promising prospects for increasing the durability aspects of concrete constructions.

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  • English

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  • Accession Number: 01522706
  • Record Type: Publication
  • Files: TRIS, ASCE
  • Created Date: Apr 16 2014 2:43PM