Potential of a Microbiologically Induced Calcite Precipitation Process for Durability Enhancement of Masonry Aggregate Concrete

AbstractIn recent times microbially induced calcite precipitation (MICP) has emerged in the cement and concrete industry as a pioneering approach to enhance concrete properties. This research was carried out with the intention to study the changed characteristics of masonry concrete, casted using brick aggregates modified by MICP. Biodeposition of CaCO3 on treated brick surfaces were detected via optical microscopy, scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and energy-dispersive spectroscopy (EDS) analysis and analyzed through quantification of calcium carbonate. Absorption tests and mercury porosimetry tests were carried out to determine the changed brick characteristics. Finally, durability parameters of modified brick aggregate-concrete were determined through sorptivity test, rapid migration test (RMT), and compressive strength test. Experiments conducted on brick aggregates reveal that MICP methods were successfully executed leading to CaCO3 precipitation. Furthermore, the modified-brick-aggregate-concrete exhibited increased compressive strength and significantly decreased permeability when compared to control specimens with untreated brick aggregate.