Experimental and Analytical Study on Geomechanical Behavior of Biocemented Sand

Research on soil biocementation has gained momentum given its advantages over ordinary Portland cement-based techniques that entail a negative environmental impact. Soil biocementation occurs when bacteria-induced urea hydrolysis precipitates calcite crystals that bind sand grains together, hence increasing both the strength and stiffness of the otherwise uncemented material. This paper presents an experimental and analytical study, simulating the geotechnical behavior of biocemented sand and explaining the precipitation mechanism of the effective calcite crystals. The experimental results of this study showed that the precipitation mechanism of the calcite crystals (calcite–silica bond or the calcite–calcite bond) plays a significant role in the strength improvement of biocemented sand, and the predictions obtained from the analytical model were found to be in good agreement with the experimental results.