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Improvement of coarse sand engineering properties by microbially induced calcite precipitation
journal contribution
posted on 2018-01-01, 00:00 authored by A Mahawish, A Bouazza, Will GatesWill Gates© 2018, © 2018 Taylor & Francis Group, LLC. This paper investigates the effectiveness of microbially induced calcite precipitation method in improving the strength and stiffness of coarse sands using treatments based on a four-phase percolation technique. An increase of biochemical treatment cycles was associated with increased deposition of calcium carbonate (CaCO3) and consequently an increase in compressive strength. Furthermore, the bio-cemented coarse sand retained reasonable porosity and permeability, which should allow dissipation of pore water pressure if required. The results also establish a correlation between the strength gained and stiffness of the bio-cemented coarse sand with the increase in the amount of deposited CaCO3, initial relative density and dry density. Scanning electron microscopy and electron dispersive spectroscopy analysis indicate that the inter-structure of the bio-cemented coarse sand tend to change in morphology based upon the number of biochemical treatments used.